ALBERT

Notes: Sterile Didinium nasutum were fed Paramecium Aurelia which had been grown on monofloral cultures of five different species of bacteria and on a wild mixed culture of bacteria. Didinia grown on monoflorally-fed paramenia or starved paramecia maintained a low daily division rate (0.88-2.06), and after 3 or 4 days died, frequently showing structural abnormalities before death. Didinia fed paramecia grown on a wild mixture of bacteria showed a higher division rate (4.96), did not die after 3 or 4 days, and encysted, when the food was exhausted. It is suggested that a diet consisting of monoflorally-fed or starved paramecia is inadequate for Didinium. This may be due to the lack of some substance or substances related to the enzyme system of the predator, possibly proteolytic enzymes elaborated by paramecia. In the experiments of Gause on the destruction of one species by another, his failure to establish population oscillations between Didinium and Paramecium might have been due to an inadequate diet for the didinia which resulted in their lack, of encystment and death.

Notes: The exoerythrocytic forms of Plasmodium gallinaceum in thin sections of infected tissue cultures have been examined with the electron microscope. It was seen that important changes occur in the fine structure of the parasite during the various phases of the cycle. The cytoplasm of the merozoites at the beginning and at the end of each cycle shows a great electron density due to a fine granulation. Larger granules are found at one pole of the parasite. The merozoites have a large nucleus in the center, and an oval body of great electron density at one pole, the significance of which is unknown. Short canaliculi can also be seen in the cytoplasm, but no mitochondria have been found.The cytoplasm of the schizonts shows a low electron density. It contains small particles scattered irregularly throughout its whole mass. The nuclei are not well defined; the oval body observed in the merozoites apparently has disappeared. Short canaliculi are present everywhere; however, mitochondria could not be identified with certainty.In the final phase of the cycle, in the rosette formations, the cytoplasm assumes again the fine granular structure. The future merozoites are grouped around a cytoplasmic core, with which they are directly connected. The whole segmenter is situated in a vacuole formation. In cross sections of the merozoites an opening in the central pole has been observed.

Notes: An account of conjugation in an American species of Blepharisma is given. A comparison is also made with the available knowledge of the two Indian species of this genus. In the conjugating pair, the condensed macronucleus shows Feulgen negative regions. Before the conjugants separate, the macronuclear and micronuclear anlagen become distinguishable.The species is characterized by a number of striking features which become noticeable after syngamy. The synkaryon divides thrice giving rise to 8 bodies. Of these, 3 to 7 become the macronuclear anlagen and the rest, the micronuclei. The resorption of the old macronucleus occurs much later, just before the exconjugant attains the vegetative form. No metagamic fissions occur in this species and each exconjugant becomes a vegetative animal in 5 or 6 days. During this period, the macronuclear anlagen arrange themselves in a series and develop slender connections with one another to produce the moniliform macronucleus of the vegetative animal. The micronuclear anlagen, on the other hand, divide by mitosis to attain the vegetative number. In this species 40% to 45% of the exconjugants are viable and the rest die.

Notes: Seven species of astomatous Infusoria from the alimentary tract of the Oligochaeta from Ochrida Lake are described. One of them, belonging to Hoplitophrya, shows many transitional characteristics between Juxtaradiophrya and Hoplitophrya and proves the coherence of the group Radio-phryinae-Hoplitophryinae-Mesnilellinae. Two species are Maupasellinae, parasites from Glossoscolecidae. Buchneriella and Maupasella, both parasites from Criodrilus lacuum, a cosmo politan worm, are also present in C. ohridensis, endemic species coexistent with the preceding, at Ohrid. Two other sro belong to Intoshellina. A discussion about the actual systematic state of Intoshellinidae is given, affinities of this family remaining uncertain. The two last species described are a typical Anoplophrya and a representative cf a new genus Corlissiella, having many morphological and biological similarities to the primitive thigmotrichs. Heterogeneity of the Anoplophryidae is discussed.

Notes: A small reversible A.C. motor is utilized in the construction of a device to tighten and loosen the caps of screw-cap test tubes.

Notes: A new species of Coccidia, Eimeria neosciuri sp. now, has been described from the squirrel host, Sciurns (Neo-sciurus) carolinensis. The oocysts (21.8-28.0 ju X 13.7-18.1) are elliptical in shape without a visible micropyle. The sporo- cysts are oval with protruding nipple. The endogenous stase; of this species occur in the epithelial cells of the villi of the upper ileum. Oocyst production declines in about a fortnight after a rise to its maximum during the first 6-10 days.

Notes: Ergosterol was isolated from the non-saponifiable lipids of Euglena. For this, after saponification of the cells, the petroleum-ether extract was chromatographed on deactivated alumina. Development was achieved by pet. ether and 10% (v/v) benzene in pet. ether, and the sterol fraction was subsequently eluted with 10% (v/v) ethyl acetate in pet. ether. This sterol was identified as ergosterol by a) precipitation with digitonin, b) The Liebermann-Burchard reaction, c) co-chromatography with known ergosterol, d) ultraviolet absorption spectrum, e) conversion to the acetate with determination of the melting and mixed melting points and !” infra-red absorption spectrum of the acetate derivative. By these techniques, ergosterol content was measured in the-following strains of Euglena gracilis under various conditions of nutrition and illumination: bacillaris and Z strains, and several albino and pigment mutants derived from them. A. functional chloroplast seems unnecessary for ergosterol synthesis; the ergosterol content of cells (dry weight basis) was constant regardless of strain and growth conditions.

Notes: The structure of the excretory apparatus of Paramecium caudatum and P. aurelia was studied in electro-micrographs of ultrathin sections. The so-called nephridial plasma visible in light microscopy was revealed as a network of fine branching tubules (nephridial tubules), of average diameter about 200 Å, which surround the nephridial canals. The nephridial tubules are connected peripherally directly to branches of the endoplasmic reticulum, which extends throughout the organism. During diastole of the radial canals the nephridial tubules open into the nephridial canals, but this connection is broken during systole. Surrounding the nephridial plasma are bundles of larger tubular elements (about 500 Å diameter).The osmiophile wall of the terminal nephridial canal continues without change in the walls of the ampulla, the injection canal and the contractile vacuole. Contractile fibrillar elements, arranged in fiat band-like bundles and of tubular structure (about 150-250 A diameter) without periodic cross-striations, begin at the top of the ampulla and extend, along the surface facing the pellicle, over the injection canal and contractile vacuole to the excretory canal, which they surround as a spiral envelope.The closing of the contractile vacuole to the excretory canal is effected by a relatively compact membrane without pores, so that the emptying of the vacuole must follow breaking of this membrane. The function of the excretory system is discussed in the light of these new observations.

Notes: Nucleic acid, the nitrogen content per cell, and cell and nuclear volume were determined in 4 green and 2 heat-induced colorless strains of Euglena gracilis and one strain of Astasia longa. All strains of Euglena were identical in cell and nuclear volume. The deoxyribonucleic acid content per cell of the apoplastidic strains was higher than that of the corresponding green strains by I1/, times. Although their nuclei were not enlarged, Feulgen staining of the colorless strains was also more intense. The significance of the increase in DNA in experimentally induced apoplastidy is discussed. As for N total nucleic acid P, and pentosenucleic acid—the dir between the strains reflected previously established morphological and physiological relationships between them. The single strain of Astasia studied was identical in stru: and size with the apoplastidic Euglena stnMH Hownner. it was quite unlike them in all the biochemical characteristic; examined.

Notes: SUMMARY. A study has been made of the cytology of an undescribed species of Spirostomum. The species is much smaller than S. ambiguum. The peristome extends to about half the length of the animal, whereas in S. ambiguum it is about two-thirds the body length. The nuclear apparatus reveals some striking differences. The macronucleus is cylindrical, and not chain-like, in the vegetative animal. The micronuclei are far fewer than in S. ambiguum and number 6–15, but are larger in size. During binary fission, the macronucleus becomes condensed into an oval or polymorphic mass and is drawn out again into a cylinder before it is cut into two lengths. The micro-nuclei divide by mitosis and, whatever their number in the vegetative animal, only 7–8 take part in the division. The others presumably degenerate.

Notes: SUMMARY. The structure and life history of a new species of eugregarine, Gregarina garnhami n.sp., is described from the intestinal caeca and mid-gut of Schistocerca gregaria Forsk. The parasite destroys considerable areas of the caecal epithelium and in cases of heavy infection, the masses of parasites present in the mid-gut result in the formation of localized barriers between the gut wall and the food material in the lumen. The cephalont and sporont stages of gregarines from Locusta migratoria migratorioides R. & F. and Anacrydium aegyptium Linn. are shown to be similar to those from Schistocerca gregaria and are believed to belong to the same species.

Notes: SUMMARY. Oxygen concentrations of 70–80 per cent of an atmosphere destroy all chromosomes of the flagellate Trichonympha provided the oxygen treatment is carried out during the early stages of gametogenesis at which time the chromosomes are in the process of duplicating themselves. This treatment does no damage to the cytoplasm and its organelles. Following the loss of chromosomes, the centrioles function in the production of the achromatic figure, the flagella, and‘parabasal bodies. Then the cytoplasm divides, thus producing two anucleate gametes which make some progress in the cytoplasmic differentiations characteristic of normal male and female gametes of Trichonympha.It is also possible, with somewhat higher concentrations of oxygen, with temperatures slightly above the freezing point and a longer period of treatment, to destroy the chromosomes of resting asexual nuclei in several genera of the flagellates that live in the roach Cryptocercus. So far as one can determine by observing organisms so treated, their cytoplasm and organelles are not injured.

Notes: Chlamydodon pedarius has peculiar and interesting cytoplasmic organelles, such as the pharyngeal basket and the cross-striped band, and exhibits plasmotomy of an uncommon type at the division stage. For comparison of the results of observations on fixed and stained material and on living material examined with phase contrast, and because of finding important differences in such a comparison, this morphological study of the cytoplasmic organelles was undertaken.The cilia, arranged in about forty rows only on the ventral surface, the anterior part of which shifts out of the dorsal body, bending to the dorsal side, are almost the same everywhere, about 5 μ in length. The cross-striped band, encircling the body surface so as to divide it into dorsal and ventral parts, has the power of movement, such as folding of the semicircular trichites and closing or opening of them. The oral apparatus, composed of a membranous system and a pharyngeal basket, is an elaborate organelle. The membranous system shows such movement as seen in a sphincter muscle, moving the triangular trichites in a manner which opens or closes the cytostome. Each of the triangular trichites is con nected with the expanded end of a long trichite; together these structures. 11–13 in number, constitute the pharyngeal basket. The ridges, the long trichites and the semicircular trichites are composed of fibrillar elements, but their twisted figures may be produced artificially by staining methods.Binary fission of Chlamydodon pedarius, under natural conditions in the season from April to October, occurs daily during the period 11 a.m. to 4 p.m. Each of the fissions takes about 2 hours. In the first half of this fission time: the V-area consisting of four central ciliary systems gives rise to transitions in the arrangement of the ciliary rows and ridges on both its anterior and middle portions; the pharyngeal basket falls down into the cytoplasm; and rosettes appear in the above two fields. On the other hand, plasmotomy arises in a fission furrow from the right side of the fission line. In the second half of the fission process, the oral apparatuses develop from the rosettes, while the old basket is dissolved into the cytoplasm; and, as the fission furrow extends leftward, two transverse bands and the frontal pellicle of the posterior daughter ciliate are organized on the surface of the fission furrow.

Notes: The centrioles of Trichonympha from termites do not differ, either in structure or function, from those of Trichonympha in Crypiocercus. The previous claims of a difference are erroneous. The roles of the centrioles in the reproduction of new extranuclear organelles and in nuclear duplication are described. The centrioles are autonomous organdies. They are just as essential for a cell's existence as are chromosomes.

Notes: A survey of protozoa was made from twelve varied sites in the region of the Mountain Lake atop Salt Pond Mountain, about 8 direct miles NNW of Newport, in Giles County, Virginia. Identifications for these sites and for 6 others previously sampled by other investigators which are recorded in unpublished reports are included. Species identified total 576; in 243 other instances genus is identified, but not species. Organisms seen but not identified to generic level are omitted. One hundred fifty-one mastigophoran species are listed; with 101 instances of generic, but not specific identification being made. Of these 102 are phytomastigophorean species; and generic placements 77 times are also listed. Seven orders, 7 suborders and 49 genera are represented. Forty-nine zoomastigophorean species are noted; and 24 other times a genus was identified. Five orders, two suborders, 18 families and 35 genera are included. Eighty-one species of sarcodina are noted. Seventy-four of these are rhizopods, and 7, actinopods. Genus, but not species was established for certain sarcodina in 52 instances. Three orders, 10 suborders, 13 families and 44 genera are represented. Ciliophora, including opalinids and suctorians, number 144 species in this list. Three are opalinds, and 141 (including the suctorians) are euciliates. In 88 observations, genus, but not species of ciliophorans was identified. Two classes, two subclasses, 11 orders, 8 suborders, 43 families and 97 genera are included. Two sporozoa are included, being unidentified species of the telosporidian genus Eimeri a, and the sarcosporidian genus, SarcocystisSome data are given relative to the nature of the sites of collection. The restricted distribution of certain organisms in certain habitats is discussed. The sites are geographically located by altitude, latitude and longitude, as well as on a map of the region.Many other protozoa are undoubtedly present in the area, the ubiquity of many protozoa being well-known. Little has been done to survey parasitic species, and other studies should later reveal more of the free-living ones.

Notes: Three strains of Hypotrichomonas acosta were isolated in axenic culture. Attempts to develop a defined medium directly from a defined medium suitable for Tetrahymena pyriformis were unsuccessful. Development of partly defined media by substitution for undefined materials in Diamond's medium were more successful. Horse serum was replaced by 1 mg. % TEM-4T (a diacetyl tartaric acid ester of monoglycerides from tallow) and 0.5 mg.% cholesterol. Yeast extract was replaced by a mixture of ribonucleotides. Inclusion of several additional components permitted reducing the Trypticase concentration from 2% to 0.25%.

Notes: An amoeba found on the fresh-water medusa, Craspedacusta sowerbii Lankester, collected in the Southampton Quarry Pond at Richmond, Virginia, is described and found to be identical with Hydramoeba hydroxena (Entz) which occurs on various species of fresh-water hydras. Transfer of the amoeba to Hydra cauliculata Hyman, and other experiments, show it to be a facultative parasite for this species. The pathogenicity of the amoeba is decreased by fouling of the culture medium; the resistance of the hydra is decreased by starvation. Hydramoeba is also capable of destroying adult fresh-water medusae in six days. Its relation to young medusae is not known, but the amoeba apparently does not attack the polyps or other developmental stages.

Notes: A Tritrichomonas foetus-likt flagellate was found in the stomach, small intestine, and cecum as well as in the nasal cavity of pigs. Xo appreciable differences in morphology or response to cultivation could be found among the trichomonads from the different sites; therefore, it is considered that they.belong to a single species, Tritrichomonas suis (Gruby & Delafond). a description of which is given. This organism could be grown indefinitely in various media, and, after a short period of cultivation, it was the only species surviving in cultures that originated from cecal samples containing 2 or 3 species. T. suis was found in the nasal cavity in 55 of 100 pigs, in the stomach in 41 (8.0%) of 512, in the small intestine in 3 of 100. and in the cecum in 215 (43.370) of 496. A T. batrachorum-type trichomonad, herein described as Tritrichomonas rotunda n. sp., was found in the cecum in 52 (10.5%) of 496 pigs. This species is typically broadly pyriform or rotund (average length 8.95 ± 0.83 ii, range, 6.83-11.4), with 3 equal or subequal anterior flagella slightly longer than the body, a relatively low undulating membrane extending y2 to 2/1 of the length of the body, and a posterior free flagellum usually a little shorter than the body. The narrow axostyle, expanded anteriorly into a curved capitulum closely associated with the large, spherical, anteriorly located nucleus, projects from the posterior surface of the flagellate for a distance which equals about 2/3 half of the body length. The parabasal apparatus is biramus. This species could be maintained only temporarily in media not containing extracts of cecal contents. A Trichomonas pronazeki-typt flagellate, found in the cecum in 126 (25.4%) of 496 pigs and in the small intestine in 1 of 100. is described as Trichomonas buttreyi n. sp. This organism is relatively small (average length 5.92 ± 0.79 μ, range 4.55-7.49). ellipsoidal in shape, with 5 to 4 flagella up to twice as long as the body, a relatively high undulating membrane of body length, a narrow axostyle with an inconspicuous capitulum closely associated with the usually oval nucleus, a projecting part of the axostyle that equals about j; of the body length, and a disc-shaped parabasal body lying dorso-lateral to the nucleus. In media without cecal extract this species could not be subcultured.

Notes: Actinosphaerium nucleofilum has been studied by light and electron microscopy. Thin sections of this organism reveal the relatively compact endoplasm to consist of numerous vacuoles and mitochondria. Scattered in the cytoplasm are dense particles, presumably ribonucleoprotein particles, endoplasmic reticulum of the rough variety and a tubular endoplasmic reticulum of the smooth variety. The many nucleido not appear to be randomly scattered in the cytoplasm but rather to be arranged in a circular pattern. Each is bounded by a double membrane envelope. A Golgi complex, consisting of isolated bodies with an ultrastructure similar to that described by others, is usually seen associated with each nucleus.The ectoplasm contains many vacuoles of varying diameter, each of which is limited by a thin membrane; vacuoles containing dense granular material, and mitochondria.The radially arranged axiopodia are extensions of the ectoplasm. The periphery is largely composed of vacuoles, some of which contain dense granules, and mitochondria. The axial rod is birefringent and consists of many fine filaments oriented parallel to the longitudinal axis of the axiopodium. The constituent filaments penetrate deep into the endoplasm where they end in the vicinity of nuclei. The fibrillar component of the axiopodia may represent contractile units.

Notes: Bresslaua vorax is a dimorphic ciliate with micro-stome and macrostome forms. The development of the macro-stome form is associated with pronounced extension of the vestibule and vestibular opening and gross torsion of the ciliate which finally shows little resemblance to the microstome form. These transformations culminate a phylogenetic trend in the Colpodidae which can be followed from the ciliates of relatively simple structure, such as Woodruffia, through Bryophrya, Colpoda and Tillina to Bresslaua. This phylogenetic trend is marked by the increasing importance of stomatogenesis. The morphogenetic pattern of these transformations appears to distinguish the Colpodidae from other trichostomatous ciliates, such as the Plagiopylidae.

Notes: Epistylis caldwelli n.sp., a β-mesosaprobic epi-biont, was collected from the surface zone of only two of 164 water bodies at Singapore. It is recorded from the neustonic mosquito larvae Anopheles (Anophele s) hyrcanus Pallas subsp., An. (Myzomyia) kochi Donitz and Culex (Lutzi a) fuscanus Wiedemann, also from corixids, Micronecta quadristrigata Bred-din, copepods, Mesocyclops leuckarti aequatorialis Kiefer, and floating dragonfly exuviae. Subsurface and benthic organisms were not infested. The squat zooids (av, 57.6 ± 34.8 μwhen fully extended) have a median contractile vacuole and a long and sinuous macronucleus. Colonies consist of 2–16 individuals on a short and unusually massive stalk up to 50 μthick.

Notes: Three new species of Caryospora (Coccidiida, Eimeriidae) are described from Psammophis sibilans phillipsi. These are C. psammophi sp. nov.: oöcysts with yellow walls, 25 to 34 μ. ×23 to 31 μ C. hermae sp. nov.: oöcysts with colorless walls, 21 to 24 μ× 20 to 22 p) and C. weyerae sp. nov.: oocysts with colorless walls, 14 to 18 μ× 13 to 17 μ, Endogenous stages of all three parasites are found in epithelial cells of the small intestine of the snake.A Caryospora from Israel is described and named C. zucker-manae sp. nov.: oöcysts spherical with outer wall crumpled. 15 to 18 μ

Notes: Cultures of tissues from ducks infected with Plasmodium elongatum supported the growth and development of the parasites for 72 hours. Cultured parasites exhibited the same properties when reintroduced into the vertebrate host as did cells derived from similar sources upon direct transfer into a new bird. Parasites derived from acute infections led to patent infections after an incubation period of 7–8 days. Parasites derived from latent infections gave rise to infections becoming apparent after 11–15 days. Results of dilution experiments show that this lag period is not due to low numbers of parasites contained in tissues from latent infections. It is concluded that invaded cells may, after the acute stage of the infection, elaborate some hypothetical inhibitor which arrests multiplication of the parasite, while not interfering with its viability or virulence.

Notes: Entamoeba invadens was studied in 8 species of snakes at temperatures of 13–14° and 25°C. Infected snakes of all species failed to show any gross pathology at 13°C, although amoebae were isolated from the snakes by culture. At the higher temperature all species showed pathological changes, most severe in Natrix, dekayi and red belly, and progressively less severe in the garter, milk, ribbon, ringneck and green snakes. For the last S species, the pathology in the liver and intestine was so characteristic as to provide an adequate basis for identification of the snake. Snakes infected at the lower temperature and later transferred to 25° showed the same pathological changes as those kept at 25° throughout. The possible effects of behavior patterns of snakes on pathogenicity of the amoebae are pointed out.

Notes: Hypotrichomonas gen nov., with a feeble undulating membrane but lacking a costa, is placed in the family Monocercomonadidae Kirby of the order Trichomonadida Kirby. H. acosta (Moskowitz) from squamate reptiles is designated as the type species. It has 3 unequal anterior flagella. The proximal part of its recurrent flagellum is attached to the surface of the body along an accessory filament. A low membrane with typically a few undulations extends between the accessory filament and the body surface. The membrane, which varies greatly in length in relation to the length of the body among strains of the species, is not supported by a costa. The recurrent flagellum continues as a free posterior flagellum beyond the end of the undulating membrane and terminates in an acroneme. The capitulum of the axostyle, spatulate or scoop-shaped, is closely applied to the anteriorly located nucleus. The capitulum extends anteriorly into a crescent-shaped pelta. The relatively stout trunk of the axostyle is straight or twisted. It projects for some distance from the posterior body surface, and the terminal segment of the projecting part tapers gradually to a point. The parabasal apparatus consists of a rod- or shaped body and of a filament or filaments.In division, the full complement of flagella in each of the mastigonts is restored relatively late during division but before cytokinesis. One of the daughter individuals retains the parental undulating membrane; the other develops a new organelle. The development of the new membrane is first marked by the appearance of an acroneme, presumably recurrent flagellum, early in division. The proximal part of this flagellum becomes progressively attached to the body surface. The process of attachment is paralleled by differentiation of the accessory filament and is followed by the appearance of the undulating membrane. The parental axostyle is resorbed during division, and each daughter individual develops this organelle de wove. In the very early stages of division the parabasal consisted of two arms and in all more advanced stages of a single rod-shaped body applied to a single filament.The significance of Hypotrichonionas in the evolution of trichomonads is discussed. Its morphology and morphogenesis suggest that this genus may represent an important step in the evolution of Trichomonadidae from Monocercomonadidae.

Notes: Two new species of Eimeria, E. megaresidua and E. longaspora, are described from the common American newt, Notopthalmus viridescens. The hosts were from the vicinity of Douglas Lake in Northern Michigan. Observations of timeof sporulation of the oocyst relative to host defecation and possible significance of the seasonal distribution of the parasites are discussed.

Notes: Plasmodium minasense Carini and Rudolph is recorded from three of 28 examples of Gonyocephalus bor-neensis (Schlegel) from Kepong and Bukit Lagong, Selangor, and P. vastator n. sp. is described from a single example of Draco volans Gray from Ulu Langat, Selangor. Both of these arboreal agamid lizards are new hosts for malaria parasites.P. vastator n. sp. is characterized by its highly amoeboid trophozoites, nucleophilic schizonts producing from four to eight (usually six) merozoites, and large (up to 22.1 ± 8.1 μ) gametocytes which alter and ultimately destroy the host cell. Forty-six other lizards of nine species, and 28 snakes of 11 species, proved negative for Plasmodium,

Notes: An X-ray induced mutant (S-16) of Chlamydomonas moewusii Gerloff lacked observable contractile vacuoles. Unlike the wild strain with vacuoles, S-16 survived only when the osmotic pressure of the medium was above 1.5 atmospheres and was provided by compounds that penetrate cell membranes slowly, like NaCl or sucrose. In solutions of such compounds, when the osmotic pressure was above 2.1 atmospheres, growth of S-16 was similar to that of the wild strain. S-16 did not grow at all in isosmotic solutions of ethylene glycol cr other rapidly penetrating compounds. Urea and glycerol, which penetrate only moderately rapidly, allowed an intermediate growth. Thus, S-16 cells are dependent upon the prevention of net inward diffusion of water.Contractile vacuoles of the wild strain were not seen when cells were suspended in solutions that allowed growth of S-16. but were visible in isosmotic solutions cf ethylene glycol or ethanol. S-16 cells ultimately burst in solutions of low osmotic pressure; large vacuole-like areas were formed but did not contract.The pulsation rate of vacuoles of the wild strain was relatively independent of osmetic pressure; vacuoles became smaller and finally invisible at higher osmotic pressures.It is concluded that the sole essential function of contractile vacuoles in C. moewusii is elimination of water.

Notes: The purification procedure for native deoxyribonucleic acid (DNA) from the green alga Chlamydomonas reinhardi is described, using a modified detergent lysis, salt extractions, and alcohol precipitations. A tracer experiment with the addition of a bacterial transforming principle from Hemophilus influenzae demonstrated a recovery of mere than 30% of the bacterial transforming principle in an extensively purified DNA preparation.

Notes: For development of flagella by myxamoebae of the true slime mold, Didymium nigripes, optimal results were obtained when they were incubated in 0.05 M NaHCOa (pH 9.1). Streptomycin inhibited flagella formation in pH 6.2 phosphate buffer but had no effect in NaHC03. The time necessary for 50% of the population of myxamoebae to become flagellated was independent of the concentration of myxamoebae; hence, the morphogenesis probably follows first-order kinetics. The acquisition of flagella was divisible into 4 stages by means of time-lapse cinephotomicroscopy: an ameboid stage, a stage of morphogenesis, an ameboid-flagellate stage, and a free-swimming flagellate stage. At least 90% of the population developed flagella within 60 min. under optimal conditions. The flagellar apparatus consists of a long and a short flagellum, each arising from a granule in the blepharo-plast. The blepharoplast is connected to the nucleus by a rhizoplast.

Notes: In order to study the blepharoplast-kinetoplast region in the adult form of Schizotrypanum cruzi thin sections of this form, obtained in tissue cultures, have been examined with the electron microscope. It has been seen that the kinetoplast is contained in a large spherical, vacuole-like space, in hich its osmiophilic mass is more dispersed than in the leishmania and crithidia forms, where it is contained in a rectangular, almost linear space. The basal body of the flagellum has been found at the margin of the vacuole, although separated from it. A group of striae in parallel array has been found with regularity in all the trypanosome forms, similar to the structures of the parabasal body in other protozoa, or to the Golgi apparatus of metazoan cells. The significance of this structure for the parasite is discussed.

Notes: Endogenous respiration and respiration in the presence of glucose of the culture forms of Endotrypanum schaudinni, Leishmania enriettü, Schizotrypanum vespertilionis, and S. cruzi, have been compared in terms of cell number and nitrogen content. Growth curves for the 4 species at 26° C. showed that E. schaudinni and L. enriettü grow faster than the Schizotrypanum in a reproducible modification of Senekjie's diphasic medium. Respiration was studied manometrically using organisms harvested in the exponential phase of growth. Res-piratory patterns at 30° C. and pH 7.2 are presented for each species. Low endogenous rates are characteristic of E. schaudinni and L. enriettii; they are relatively high in both Schizotrypanum spp. The respiration of E. schaudinni is stimulated from 5.3 to 36.1 times by glucose; that of L. enriettii from 5.2 to 9.7 times and that of the Schizotrypanum from 1.9 to 5.7 times. Carbohydrate is of great importance for the survival and motility of E. schaudinni and L. enriettii, but plays a relatively minor role in Schizotrypanum.

Notes: A study was made of the effects of solar radiation, temperature, relative humidity, centrifugation, oxygen, pH, and certain chemical agents on the sporulation of oocysts of Eimeria zurnii of cattle. Of various chemical agents and bactericides tested, only HgCl2 exhibited a high level of activity against unsporulated oocysts. Extreme pH values of 1 and 13 did not alter sporulation. Oocysts required at least 10% of the normal amount of oxygen to sporulate at a normal rate. Physical factors found to be lethal for E. zurnii were: sunlight for as short a time as 4 hours, drying at 25% or less relative humidity, and freezing below about -7° C. Survival was directly proportional to relative humidity, but within the limits of the observations reported here, there was no correlation with time or temperature. Normal sporulation occurred from about 8° up to 32.5° C. Below 12° the time required for sporulation was exceedingly long, and at 35° sporulation was morphologically abnormal. The optimal temperature for sporulation was about 30° at which temperature some organisms completed the process in 23 hours. Fifty % of the oocysts required 65 hours to begin sporulating at 20° and 36 hours at 25° C.

Notes: Dimorphic populations of Tetrahymena patula L-FF result when this organism is grown axenically in Loefer's medium supplemented with aqueous lettuce extract. The two different cell types in these cultures are identified as “macrostomes”and “microstomes.” Isolation of microstomes and macrostomes from the dimorphic cultures has shown that both cell types reproduce by binary fission in this medium, and further that each cell type will occasionally give rise to the other under these conditions. Isolation experiments have also shown that both microstomes and macrostomes from the dimorphic cultures are capable of giving rise to the reproductive cyst. The cells which are liberated from the cyst have small mouths but are best referred to as “tomites,” in order to distinguish them from the self-perpetuating microstomes described above. The relatively small, rapidly swimming tomites will either transform into macrostomes or reproduce as microstomes. The life histoy of T. patula thus consists of three cell types as follows, each capable of giving rise to the other two: a macrostome, a microstome, and a tomite. Silver preparations of the dimorphic cultures have shown that oral replacement takes place. This consists of resorption of the oral apparatus and its replacement by differentiation of new mouth parts from an anarchic field of kinetosomes which arises immediately posterior to the old oral apparatus. It is suggested that this process is involved in the macrostome-microstome interconversions.Growth curves were determined for T. patula feeding on a variety of substrates. These data indicate that this species is extremely well adapted as a carnivore. It grows very poorly on bacteria, but will grow well in axenic culture if aqueous lettuce extract is provided. The lettuce extract greatly reduces the generation time and increases the maximum cell density.Loss of the micronucleus in stain L-FF is reported and discussed. The loss may be an indication that this strain has entered the senile phase of the Maupasian life cycle.

Notes: A method is described whereby large amounts of Euglena cells can be obtained efficiently for enzymological studies. A completely defined, low pH medium which offers relative freedom from contamination is usee The cuh re-equipment is also usable for the mass culture of many other unicellular algae.

Notes: Thecamoeba sphaeronucleolus, and other verrucosid amebas with thick, pellicular ectoplasm, which live in moist soil, can identify the presence of testate rhizopodal prey at distances of 20 to 30 μ, possibly chemotactically or rheotacti-caliy. Prey is seized by extension of a pseudopod towards it, and adhesion of the pellicular pseudopodal tip to the prey upon contact. Ingestion is accomplished by conversion of the pellicular coat of the pseudopod into an ingestive tube via digestion of the pellicular tip and the withdrawal of the endoplasm within, causing suction. The prey is drawn into the tube and enclosed therein; and is then drawn down the pseudopodal tube and into a food cup, which closes around the prey to form a food vacuole. Flagellate prey is identified by its movements nearby, and is seized by adhesion of the extended pseadopod to a flagellum. The flagellum is drawn through a tiny hole digested by the ameba through the pellicle of its psendopod. is seized by and drawn into the granular endoplasm. The body of the flagellate is drawn after it into a food vscuoie in the endoplasm. Suction applied to the flagellum appears to exert the necessary force to draw the flagellate in. The movements involved are related to, but not synonymous with, those of locomotion and appear to be complex biochemical and biophysical interactions not explainable by present theories of protoplasmic movements.

Notes: SUMMARY. Known chemical compounds have replaced the three supplementary factors previously necessary for the growth of Euplotes patella feeding on Chilomonas paramecium under bacteria-free conditions. The factor found in an extract of liver was identified as thiamine. The factor supplied by extracts of certain bacteria has been tentatively identified as folinic acid. A combination of 8-azaguanine and the riboflavin analog, flavotin, has been substituted for the factor found in yeast extracts. Inorganic salts and sodium acetate have been incorporated in the supplementary medium to promote the growth of the flagellate food organisms. Euplotes has also been cultured on Tetrahymena pyriformis in a medium containing 8-azaguanine and flavotin. The requirement for supplementary growth factors in this carnivorous ciliate has been interpreted as definitely involving intermediates in purine metabolism.

Notes: SUMMARY. An improved assay of vitamin B12 is described. The z strain of Euglena gracilis, which grows more vigorously than the bacillaris strain previously used, is recommended. The pattern of B12 specificity of the two strains appears to be the same. A new medium containing sucrose, aspartic acid, glutamic acid, and glycine at pH 3.6 is well buffered and allows luxuriant growth. Vigorous utilization of sugar appears to depend on readily available nitrogen and a Krebs-cycle component; these requirements are well met by aspartic acid (or asparagine) and glutamic acid. The proposed procedure is especially suitable for the measurement of B12 in blood serum because rise in pH and precipitation of serum proteins during incubation are minimized. Like bacillaris, the z strain allows the distinction between “combined” and “uncombined” B12 in serum. Serum may be an appropriate test material to tell whether such phagotrophs as Peranema can better utilize bound forms of vitamins than can the related osmotrophs. Patterns of B12 requirements and occurrence are discussed as phylogenetic markers.

Notes: SUMMARY. Cells from a clonal culture of Tetrahymena pyriformis W were cultured in the presence of 10-4 M KCN for a prolonged time until they became “adapted” to cyanide. The effect of 10-3 M KCN upon respiration in the “adapted” cells was compared with the effect upon “normal” cells of the same clone grown in the absence of cyanide. The direct method of Warburg was employed.Adapted cells are more resistant against respiratory inhibition than are normal cells. Resistance is due both to a factor or factors retained within the cell and the extracellular factor(s) released into the medium by the adapted cells during their growth. The intracellular factor is acid labile, and apparently may be developed within a short time. The extracellular factor is heat labile and may cause normal cells to be more resistant against respiratory inhibition by KCN.Resistance to respiratory inhibition is lost if adapted cells are cultured in the absence of KCN. It is proposed that changes involved in gain or loss of cyanide resistance are due to physiological adaptation and not to the usual genetic influences.

Notes: SUMMARY. A neopeptone blood broth was a satisfactory medium for cultivation of the frog trypanosome T. ranarum, though it did not support as consistently good growth as the corresponding diphasic medium. The superiority of diphasic over liquid medium could be explained only by the presence of a reserve of nutrients in the agar slant which diffuse into the liquid phase. Inocula from culture tubes 12 days or less in age resulting from a succession of rapid transfers appeared to be necessary for maximal growth.

Notes: SUMMARY. Great numbers of a new ameba have been collected from freshwater, lagooning, disposal tanks for citrus pulp wastes. The ameba is morphologically similar to the marine Flamella magnifica (Schaeffer, 1926), and clearly belongs to the genus. It differs sufficiently in the formation and characters of locomotor organelles, and in habitat, to be considered a separate species, Flamella citrensis n. sp.

Notes: SUMMARY. The enzymatic induction of fatty acid oxidase activity in Polytoma can be characterized as follows: (1) the preferential synthesis of oxidase activity can be induced in non-proliferating cells, (2) the rate of induction is dependent upon the concentration of exogenous nitrogen, (3) the rate of induction is also dependent upon the age of the cells, (4) with log-phase cells, the rate of synthesis is highest and the kinetics of synthesis, linear; the rate of synthesis by older cells is low and variable in form, (5) ultraviolet irradiation selectively inhibits induction at doses which do not inhibit respiratory activity, oxidative assimilation or nitrogen utilization.

Notes: SUMMARY. The trichomonad occurring in the nasal cavity of the domestic pig, Sus scrofa, is described and figured. With Heidenhain's iron-hematoxylin and protargol (protein-silver) stains, the specific characters are as follows: Pyriform in shape; length 8.8–18.4 μ (average 13.6 μ); width 3.2–8.0 μ (average 4.8 μ); blepharoplast of several granules; three anterior flagella with the longest 10.4–16.8 μ in length ending in knob-like enlargements; full length undulating membrane with four to six subequal folds and containing marginal and accessory filaments; trailing flagellum 4.8–11.2 μ in length; full length costa with fine subcostal granules; hyaline rod-shaped axostyle with bulbous capitulum, chromatic ring and conical tip; tube-like parabasal body 3.2–4.8 μ in length; oval-shaped nucleus 3.7–5.0 μ in length and 2.2–3.0 μ in width; cytostome; and vacuolated cytoplasm containing food vacuoles.Taxonomy of trichomonads in the respiratory and digestive systems of swine is discussed and the nasal trichomonad is compared with the two different forms of Trichomonas found in the cecum. The conclusion is that the nasal form is of a different species from the trichomonads of the cecum. The close similarity between the nasal form and Tritrichomonas foetus is emphasized. The writer suggests that the nasal form should not be given recognition as a new species until its true relationship with T. foetus is revealed.

Notes: SUMMARY. Saprophilus muscorum Kahl, 1931 is an edaphic species which has been identified in cultures of soil and forest litter. This ciliate has the buccal ciliary apparatus of the family Tetrahymenidae Corliss. There is only one post-oral meridian and 15 bipolar meridians, 8 of which meet ventrally at the pre-oral suture. The cilia are long and sparse and there is a prominent longer caudal cilium. Trichocysts are present. Resting or resistant cysts are formed readily.

Notes: SUMMARY. To determine whether Tetrahymena pyriformis could infect Deroceras reticulatum and become morphologically modified in the same way as the parasitic phase of T. limacis, 50 slugs were exposed for 10 days to an amicronucleate clone of T. Pyriformis and 50 were exposed for the same period of time to a micronucleate clone. The slugs were then transferred to clean containers for another 10 days, to allow ciliates which had entered the slugs either to persist and multiply or, in the case of transitory infections, to disappear. An additional 50 slugs were kept in a control group for 20 days. All of the slugs had been collected at a single locality in which natural infections by T. limacis had not been noted, and were maintained in separate one-half pint milk bottles throughout the experimental period.Of the slugs exposed to the amicronucleate clone, 40 survived to the end of the experimental period, and 15 were infected. Of those exposed to the micronucleate clone, 42 survived, and 5 were infected. Forty-three of the slugs in the control group survived, and none were infected by ciliates. In some of the slugs infected by T. pyriformis, hundreds of ciliates were noted. The infections were apparently limited to the digestive gland, intestinal tract, and fluid around the viscera. Ciliates recovered from slugs were in general smaller than those growing in thriving cultures, but morphologically were typical T. pyriformis. None were observed to have a proportionately smaller cytostome or apiculate anterior end characteristic of the parasitic phase of T. limacis.

Notes: SUMMARY. The aggregative process of Dictyostelium discoideum is unaffected by most chemical and physical alterations of the environment. Such substances as vitamins, amino acids, catabolic intermediates, purines and pyrimidines, redox poising agents, enzyme inhibitors, and inorganic salts were added to the aggregative substrate. Of these, only a few exerted any influence on aggregation except at lethal concentrations. Histidine allowed the wild-type myxamoebae to aggregate at lower population densities and accelerated the aggregative process as compared with controls on minimal agar. Brief exposure to histidine irreversibly conditioned the cells. No degradation of the imidazol skeleton was detected. A rise and fall of internal soluble histidine were demonstrable. The purine base, adenine, raised the population density required for maximal center formation.

Notes: Using the mite Dermanyssus gallinae as the vector and the canary (Serinus canariu s) as the avian host, the author was able to demonstrate the transmission of the parasite Lankesterella (=Atoxoplasm a) garnhami Lainson, 1959. Mites were taken from infected canaries and fed to clean ones; 3 out of 4 birds became infected. Mites taken from infected sparrows (Passer domesticus domesticu s) were fed to 4 other clean canaries, all of which became infected. Natural transmission of the parasite was achieved when 2 clean canaries were exposed to infestation by mites which had previously fed exclusively on infected sparrows. Six control canaries, obtained from the same source as the experimental birds, were all shown to be uninfected. It is concluded that the parasites in the sparrow and the canary are identical. The specific name of Lankesterella serini Lainson, 1959, for the organism in the canary becomes, therefore, a synonym of L. garnhami Lainson, 1959.

Notes: The techniques of silver impregnation and of digitonin solubilization have been applied to an investigation of aspects of cortical morphogenesis in Glaucoma chattoni. The typical stages of the formation of new oral areas (stomato-genesis), as well as of other related surface events, are described in detail. Estimates were made of the relative and absolute durations of these stages; these estimates indicate that for animals growing at 25°C. in bacterized culture, stomatogenesis and cell division together occupy about one third of the division cycle.Certain atypical morphogenetic phenomena have been encountered and are briefly described. These include three cases of stomatogenesis along a kinety other than kinety 1, several instances of anterior stomatogenesis leading to replacement of existing oral areas, and numerous cases of spontaneous loss of oral areas.Finally, the process of increase in number of kinetosomes along certain kineties has been submitted to intensive study. It has been found that comparatively little increase takes place during stomatogenesis and cell division; the bulk of kinetosomal increase along the kineties takes place during the first two-thirds of the division cycle. Data relevant to this increase have been analyzed according to the method of Scherbaum & Rasch; this analysis reveals that the probable phases of most rapid kinetosomal increase, along kinety l at least, occur just after division, and just before the beginning of stomatogenesis.

Notes: Certain polyoxyethylene ethers, derived from p-tert.-octylphenol and representatives of series which have activity against murine tuberculosis and leprosy were tested in several protozoal infections. Triton WR-1339 represented the series in which the phenolic groups are arranged linearly while HOC-12½ and LOC-60 represented series in which the phenolic groups were condensed into a cyclic structure. WR-1339 was found to be active against infections with Trypanosoma gambiense, T. rhodesiense, T. brucei, T. congolense, and T. equipevdum in mice, and against Leishmania donovani in the golden hamster. The “macrocyclic” HOC-12:4 also had activity, but of a much lower order, against the first three trypanosome infections listed, and in leishmaniasis it had activity equivalent to that of WR-1339. Neither of these compounds was active against Trypanosoma cruzi, Plasmodium berghei nor Toxoplasma gondii in mice, nor against Leptospira icterohemorrhagiae in guinea pigs. The other macrocyclic compound, LOC-60, was inactive in the infections in which it was tested (T. congolense and T. rhodesiense).Although the action of the polyoxyethylene hers in murine tuberculosis and leprosy had been reported to be an indirect one, affecting the host rather than the mycobacteria (which are said to be resistant to these materials in vitro) it was found that the differential effects in trypanosomiasis, observed with WR-1339 (which had good activity in vivo) and HOC-12½ (which had poor activity in v i v o), were well correlated with their effects in vitro. In the light of the strength of the dilutions which killed T. congolense in the t a t tube and the blood levels of WR-1339 obtaining after medication the control of the infection could be attributed to the direct action of the compound on the parasite although some indirect effect on the host, perhaps of the nature of reticulo-endothelial stimulation, could not be excluded.

Notes: The use of saponin hemolysis, buffer washings and deoxyribonuclease yields quantities of erythrocyte-free plasmodia sufficiently pure for physico-chemical studies. The pigment produced by Plasmodium lophurae, unlike the pigments of the simian and human malarias, is of such low solubility in buffer solutions that urea is necessary as an additive to the buffer for adequate solubilization. On the basis of spectral and electrophoretic qualities, the pigment is a protein-porphyrin complex closely resembling methemoglobin but clearly distinct from hematin. Extraction of the pigment in solvents which degrade hemoglobin, e.g. phenol, 0.1 N NaOH, cannot be used to ascertain the properties of hemozoin, for the pigment in such solvents shows a spectrum identical to hemoglobin.The soluble parasite proteins which constitute approximately 55% of the totaI volume of the parasite as revealed by electrophoretic and ultracentrifugal analysis appear to be homogeneous. They show a marked similarity to the host hemoglobin, but differ sufficiently to verify their integrity and individuality.

Notes: Stomatogenesis in Paramecium aurelia is shown to involve the lower kineties of the right vestibular wall, the endoral membrane and perhaps the quadrulus. The anarchic field for the new buccal organelles is formed by granules produced from somatic kinetosomes of the right vestibular wall. The endoral membrane becomes incorporated into the buccal anlage and probably regulates orientation and development of the new organelles. A production of heretofore unobserved buccal kinetosomes from the quadrulus is described and it is suggested that these may form the new endoral membrane for the proter.During conjugation the infraciliature dedifferentiates in the area of fusion between the conjugants. The buccal organelles dedifferentiate at the time of pronucleus formation and transfer. It is suggested that dedifferentiation of structures in the fusion area is caused by a partial solation of the cortex in this area. The dedifferentiation of the buccal organelles results from the solation of the cytoplasm and the cortex of the paroral cone during pronucleus migration. The redifferentiation of the buccal organelles and somatic kinetosomes is suggested to be a recrystallization or gelation of the cortex with the structures re-forming in their normal positions and not from an anarchic field as at fission.

Notes: When exogenous ecdysone is injected into a host (adult or intermolt nymph) which has no ecdysone of its own, gametogenesis is induced in the protozoa of such a host, although the host itself never undergoes ecdysis. The time required to induce this sexual process varies in different genera and with the dosage of hormone administered; but it is never possible, regardless of the amount of hormone given, to induce gametogenesis in all the genera at the same time; some still begin a day or two later than others, but never 40-45 days later as occurs in untreated roaches.Likewise, when exogenous ecdysone is administered to a nymphal host in the molting period, the sexual cycles of its protozoa are greatly accelerated, and the host undergoes ecdy-sis much sooner than would otherwise have been the case. Both sexuality in the protozoa and the molting process in the host are accelerated. Only when large doses of ecdysone are administered are the sexual cycles of the protozoa modified in any way except a decided acceleration. Quite large amounts of ecdysone present special problems for the protozoa, problems they never encounter in nature. The growth and differentiation hormone ecdysone causes the protozoa to grow and differentiate so rapidly that many of them cannot keep pace; as a result, degeneration begins, and death follows. But this over-acceleration effect of ecdysone and death of the protozoa occurs only in those genera which have not undergone gametogenesis when the large amount of hormone is administered; those which have completed gametogenesis are not affected at all. The results of acceleration have been observed in most genera, but have been studied more intensively in Tricho-nympha, where they are usually seen to be considerably more pronounced on the nuclei and chromosomes than on the cytoplasm. As a result, this genus, which invariably in nature undergoes only fertilization, is sometimes made to undergo either autogamy or endomitosis. The pronuclei, for example, differentiate and are ready to (and do) fuse before the cytoplasm of the gametocyte divides to form gametes. In the case of endomitosis, precocious differentiation of chromosomes seems to produce, or at least goes along with, premature degeneration of one centriole, the one that would ordinarily degenerate following fusion of gametes. Thus, nuclear division is made impossible.In some genera of the protozoa, the ecdysone titer must drop greatly before meiosis can begin. If the titer, after ecdysis. when it normally drops precipitously, is kept high with injections, meiosis does not begin; it is retarded for as long as the ecdysone titer is kept high.

Notes: Over ninety genera of ciliated protozoa have been given names preoccupied by the generic names of other animal organisms. To date some sixty of these junior homonyms never have been corrected. In half of these cases the homonymous ciliate names have been buried as synonyms of one kind or another, however, and need be of no further practical concern. For the remaining genera, thirty in number, replacement names arc proposed in the present paper in accordance with provisions of the International Rules of Zoological Nomenclature. Such action is considered to be in the best interest of ultimate taxonomic stability among the groups of organisms involved. New names also have had to be proposed for five families or subfamilies whose type genera have lost their original names through homonymy.

Notes: Paramecia, in a nearly defined axenic medium, require a specific fatty acid and a “protein” factor for growth and survival. The fatty acid requirement was readily satisfied by stearic acid or oleic acid. The saturated acids, arachidic (C20) and one preparation of palmitic (C16), had lower growth activity than did stearic acid. The unsaturated fatty acids palmitoleic (C16Δ9), linoleic (C18Δ9,12), linolenic (C18Δ9,12,15), and arachidonir (C20Δ5,8,11,14) and the saturated fatty acids of C14 through C6. myristic, lauric, capric, caprylic and caproic, were inactive. A few other fatty acid-containing compounds. i.e., esters, were also tested for growth-promoting activity, with concordant results.The “protein” factor has not been completely characterized; a nondialyzable protein-containing fraction from yeast or crystalline ovalbumin provided it. Hydrolysis products of these substances were inactive. A possible role of the ovalbumin as a carrier for fatty acids is discussed.

Notes: The kinetoplast and associated structures in Leishmanial tropica, Trypanosoma cruzi, T. lewisi, Herpeto-inonas culicis, H. muscarum and Crithidia fasciculata have been studied by electron microscopy of thin sections. The kinetoplast appears as a mitochondrion within which are antero-posteriorly oriented anastomosing fibers. In the three species parasitic in vertebrates there is a sharply delimited anterior zone where these fibers are thick and electron-dense. In the insect parasites the fibers form a looser network of approximately uniform density from anterior to posterior.The blepharoplast is the 9-fibered cylinder forming the base of the axoneme and extending below the base of the reservoir. A diffuse mass of electron-dense material surrounding this is the basal granule, visible also with the light microscope.The contractile vacuole appears in electron microsraphs as a clear area associated with Golgi material.

Notes: Stages in the life-cycle of the coccidium Eimeria neosciuri Prasad(12), from the epithelial lining of the small intestine of Sciurus carolinensis Gmelin are described, with particular reference to the endogenous phases. The pathology, sporulation and rate of oocyst production are determined, and a discussion on known coccidia from related Sciurus spec: included.

Notes: A study by means of paper electrophoresis of the scrum.proteins and lipoproteins during the course of infection of chicks with Plasmodium lophurae, reveals a qualitative change in the gamma-globulin and demonstrates: a significant crisis period depression of the albumin; no alteration of the alpha-globulin or alpha-lipoprotein; a significant crisis period rise in the beta- and gamma-g'obuiins with the former persisting in higher amounts well after the crisis of the infection. The significance of such changes with reference to previous work and the induced pathology is discussed.

Notes: Thin sections of Plasmodium, cathemerium obtained 3 to 10 days after ingestion of blood by mosquitoes were examined by electron microscopy. Oocysts are encased in a relatively thick structureless capsule which becomes progressively thinner with advancing age and completely disappears in places at the time of release of the sporozoites. The capsule blends with and in most cases cannot be distinguished from the “elastic” layer of the mosquito stomach. For this reason the capsule is tentatively regarded as a product of the host rather than of the parasite. Capsular material appears to be shed into the interior of the oocyst and may serve as nutrient material in the later stages of development. Oöcysts and sporozoites contain mitochondria, endoplasmic reticulum and nuclei with nucleoli at all stages examined.All limiting membranes within the oocyst are feebly developed and no cell boundaries are seen until the sporozoites begin to form. At this stage, the sporozoites acquire very prominent surface membranes which are retained by the mature forms.Sporozoites contain long rods and cylinders of homogeneous material of moderate density. Their functional significance is not understood.

Notes: Hysterocineta eiseniae, from the oligochaete Ei-senia lonnbergi, and Ptychostomum campelomae sp. nov., from the fresh-water prosobranch snail Campeloma geniculum, have been studied primarily with a view to arriving at a better understanding; of the adoral and buccal ciliature of hystero-cinetid ciliates. In both of these species (as well as in representatives of two undescribed genera), the arrangement of adoral and buccal ciliary organelles is fundamentally the same. There are three adoral rows of cilia extending transversely across the posterior end of the body, toward the buccal cavity. The row nearest the superior surface consists of cilia which are fused into a hyaline and relatively inactive membrane. This row enters the buccal cavity on its left side and extends inward to the cytostome. The other two rows, inferior to the membrane, are close together and consist of active and coherent cilia which collectively form a brush-like complex. Oi these rows, the one nearer to the membrane enters the buccal cavity on its right side. The other row ends at the right side of the buccal overture, and near the point where it terminates, but on the opposite side of the continuous row, a similar series of cilia originates and closely parallels the continuous row to the cytostome.The diagnosis of the family Hysterocinetidae is emended on the basis of this characteristic arrangement of the adoral and buccal ciliature. The hysterocinetids appear to be rather closely related to ciliates of the family Hemispeiridae, and are therefore tentatively referred to the order Thigmotrichida.

Notes: 3-Amino-l,2,4-triazole (AT) stops multiplication of the photosynthetic protists, Ochromonas danica, O. mal-hamensis, Euglena gracilis var. bacillaris. and Rhodopseudo-monas palustris; it also stops growth of the multicellular plant, Spirodela oligorhiza. O. danica and S. oligorhiza are the most sensitive. AT is about equally inhibitory to algal flagellates grown in the light or dark. Porphyrin biosynthesis is suggested as the probable site of inhibition by AT. Both AT and streptomycin (SM) bleach all the above organisms. Bleaching is permanent only in SM-bleached E. gracilis; all the other organisms become fully pigmented when placed in inhibitor-free media. The uniqueness of the SM-bkaching of E. gracilis is discussed.

Notes: Food vacuoles have been studied in various stages of the digestive process in cultures of Pelomyxa carolinensis and P. illinoisensis after feeding Tetrahymena and Paramecium. The vacuole wall formed immediately after capture of the food organism may be only 100 m/i thick. The changes observed in the food organisms indicate that first the membranes of the pellicle are ruptured, then mitochondria, cytoplasmic matrix, and nucleus are attacked; cilia and trichocysts are more resistant. The food vacuole membrane is involved first in the removal of water from the vacuole, then in transfer of cytoplasmic fluid into the vacuole, and finally in removal of digestion products from ihe vacuole by pinocyt. Vesicles which have been derived from the plasnulf—a b pinocytosis have been observed. They characteristically have a non-turgid, non-spherical appearance when located deep m the cytoplasm and are stainable with phosphotungstic acid. Pinocytosis and the function of food vacuole membranes are discussed. It is concluded that at leait two factors contribute to the benefits derived by amoebae from pinocytosis: (1) modification of the plasmalemma membrane near the time when it becomes the pinocytic vesicle membrane, and (2) increased surface area for diffusion.

Notes: SUMMARY. The central canal of the suctorial tentacle of Ephelota is limited by a fine pellicle composed of numerous longitudinal fibrils and bearing 16–18 membrano-fibrillar ridges arranged radially in the lumen of the canal. This structure resembles that of the myonemes in the heterotrichous ciliate Stentor.The prehensile tentacle of Ephelota contains 4–6 axial protein fibers each consisting of a lamello-fibrillar bundle and isolated from one another by thin intracytoplasmic membranes.In both types of tentacle the cytoplasmic portion is immediately limited by a very thin pellicle which is continuous with the “epiplasmic membrane” and covered by the alveolar cuticle which envelops the entire body of the ciliate.

Notes: SUMMARY. A medium is described for the axenic culture of Paramecium multimicronucleatum which is chemically defined except for one constituent—a nondialyzable fraction (NDF) of an exhaustively dialyzed yeast extract. Using this medium it has been possible to demonstrate an absolute requirement for stigmasterol and the following B-vitamins: folic acid, riboflavin, thiamine and pantothenic acid. There was evidence that nicotinamide and pyridoxal are also required for continued growth of the organisms. The nitrogen requirements could be met with any of the following: proteose peptone, purified casein, crystalline ovalbumin, or a mixture of amino acids. A carbon source, in addition to that supplied by the NDF or the amino acids, was essential. Sodium acetate and sodium pyruvate would satisfy this requirement.

Notes: SUMMARY. Pleurotricha lanceolata was cultured in an aqueous extract of Cerophyl with Tetrahymena sp. as the primary food organism. It was induced to form resting cysts by crowding in the absence of food in a modified Osterhout solution. Cysts formed in this medium remained viable for several months.The morphology of the cysts and of animals undergoing excystment was studied both in the living state and in stained preparations. The excystment process was recorded by camera lucida drawings. These studies revealed no endomictic nuclear reorganization, and no extrusion of nuclear material as had been previously reported.An analysis of certain chemical and physical factors which affect excystment showed the following: the rate of excystment is temperature controlled; increasing the pH of the excystment medium increases the time required for excystment; in low concentrations some aqueous plant extracts are effective excysting agents; dilute solutions of certain plant acid mixtures neutralized with KOH are likewise effective; a number of organic substances, e.g., Bacto-yeast extract and Bacto-peptone, are also effective; and the presence of bacteria retards the rate of excystment.

Notes: SUMMARY. Measurements of the length and width of a total of 6,915 unsporulated oocysts of Eimeria necatrix from 11 infected chickens revealed a length range of 12.1-28.9 μ, width range of 10.8-23.8 μ, and a shape-index (length/width) range of 1.0-1.64. The average size range of the samples of 25-100 oocysts (mean, 66 oocysts) constituting this total and taken on the various days of the patent periods was 15.6–23.9 μ× 13.9–19.5 μ. The lengths, widths and shape indexes of the oocysts constituting such samples usually described unimodal, near-normal frequency distribution curves.The average size of oocysts issuing from an average chicken on an average day of the patent period of the infection was, with standard deviations, 19.7 ± 1.82 μ× 16.7 ± 1.20 μ. The average standard errors for the length and width were 0.237 μ and 0.158 μ, respectively, in samples of the size indicated. A tendency to increase slightly, though significantly, in size after the first three days of the patent period was noted; also, a slight, though significant, linear increase from the first to the seventh day, inclusive. A slight, though significant, tendency to shorten with the passing of the days of the patent period was detected.Analysis of variance revealed much variation in oocyst size from bird to bird on a given day and for given bird and day combinations, but significant day to day variation was demonstrated for width only. By splitting the variance during the first seven days of the patent period into its parts, it was determined that the mean oocyst size during this period was, with standard errors, 19.59 ± 0.238 μ× 16.63 ± 0.200 μ. Further analysis disclosed that a considerable reduction in oocysts measured could be accomplished, with no loss of accuracy, if fewer measurements were taken per bird and more birds were employed.

Notes: SUMMARY. Spirobutschliella clignyi, which occurs in the intestine of Pomatoceros triqueter, was found in numbers ranging from 1 to 98 in about 45% of the host specimens examined at Drøbak. Comparative incidence of infection in closely neighboring host specimens suggests that migration of normal sized ciliates is not the main route of infection. The distribution of dwarf ciliates indicates the possibility of their being involved in transmission. The general morphology and the absence of skeletal structures would seem to permit inclusion of the species in the family Anoplophryidae.

Notes: SUMMARY. Three enzymes of the glycolytic pathway, hitherto not identified in Trichomonas vaginalis, have been studied: phosphoglucomutasse, α-glycerophosphate dehydrogenase, and lactic dehydrogenase.The identification of seven phosphorylated glycolytic intermediates is reported.The operation of glycolysis in T. vaginalis is postulated from enzymatic as well as chemical studies.

Notes: SUMMARY. Sodium pyruvate, glutathione, potassium cyanide, dextrose, sucrose, 3 nucleic acid derivatives, 11 B-vitamins, and 22 amino acids were tested for their ability to protect Astasia longa against the lethal damage induced by ultraviolet radiation. Compounds which protected when added to a cell suspension just before irradiation were cystine, phenylalanine, tryptophan, tyrosine, adenine, cytidylic acid, uracil, and sodium pyruvate. None of these compounds protected when added immediately after irradiation. Except for phenylalanine, solutions of these compounds afforded protection when used as filters between the ultraviolet source and the flagellates. Cysteine failed to protect when added just before irradiation, but gave good protection when cells were grown in its presence.

Notes: SUMMARY. The number of complete primary ciliary meridians in Tetrahymena limacis found in natural infections in the slug Deroceras reticulatum has been observed to range from 32 to 40. To study the range in the number of meridians in clones in culture, 10 ciliates were pipetted singly from each of two natural infections into sterile 1% (w/v) yeast extract to which 400 units of potassium penicillin-G and 500 micrograms of dihydrostreptomycin sulfate per ml. had been added aseptically. Ten ciliates were also pipetted from each of these natural infections into infusions of tissue of the digestive gland of D. reticulatum. Altogether, 28 clones (13 axenic clones in yeast extract and 15 bacterized clones in tissue infusions) were established.The shape of ciliates in thriving axenic cultures is generally ovoid or pyriform, and similar to that of ciliates in bacterized cultures. However, ciliates in axenic cultures are sharply apiculate at the anterior end and free from inclusions other than small lipoid granules, and in these respects resemble ciliates of the parasitic phase. The cytostome of ciliates in bacterized and axenic cultures is larger in proportion to the size of the body than it is in the parasitic phase.The ranges in the number of ciliary meridians in ciliates of the two natural infections from which the clones were established were 33 to 40 and 32 to 38, whereas the number of meridians in the clones taken as a whole ranged from 25 to 32. Fifteen of the clones showed extremes of 26 and 30.One of the clones was re-introduced into D. reticulatum by exposing 50 slugs to a culture of the ciliates for 10 days. The slugs were then transferred to clean containers for another 10 days. Forty-one of the slugs exposed to ciliates survived the experimental period, and 32 became infected by T. limacis. Forty-four of 50 slugs in an unexposed control group survived, and none were infected by ciliates. In the ciliates from slugs of the experimental series, the number of complete primary meridians ranged from 28 to 36. However, more than half of the ciliates in the experimental infections possessed incomplete rows, and some individuals had as many as five of these. Ciliates in natural infections and in cultures sometimes have incomplete rows, but rarely show more than one such row. The incomplete rows in ciliates re-introduced into slugs are considered largely to be incipient segments of future complete rows. They occur most commonly in the post-oral region, and particularly between row 1 (the so-called stomatogenous meridian) and the next complete row to the observer's right. It appears, therefore, that the post-oral region is a zone in which most new rows are proliferated.

Notes: SUMMARY. Manometric and culture experiments were designed to study factors influencing the metabolism of Trichonympha from Zootermopsis. A starvation period of 36–44 hours for the termites lowered the endogenous metabolism of Trichonympha and made possible the testing of substrates in the Warburg apparatus. In the presence of antibiotics, cellulose and cellobiose were utilized at approximately the same rate by the protozoa. Yeast extract stimulated cellulose fermentation in Trichonympha from starved termites, but the effect could not be demonstrated in protozoa from recently fed termites. Yeast extract, blood serum, and liver fractions improved the survival of the flagellates in anaerobic cultures.

Notes: SUMMARY. The peduncle of the chonotrichous ciliate Chilodochona is composed of a bundle of protein fibers secreted by intracytoplasmic glandular ampullae. This process, very different from that involved in production of the peduncle in the peritrichous ciliates, also is found, although with a simpler result, among the Dysteriidae, a highly evolved family of gymnostomes closely related to the chonotrichs.

Notes: SUMMARY. A new actinomyxid, Triactinomyxon naidanum, distinguished from other members of the genus by having 12 sporoplasms, is described from the intestine of an Indian fresh-water oligochaete, Nais communis punjabensis. This is the first finding of an actinomyxid in Asia and also the first finding in a member of the family Naididae.

Notes: SUMMARY. A new species of Tetrahymena is described, the ninth to be allocated to this genus. Most significant morphologically and taxonomically is its possession of a single, slender caudal cilium, twice the length of the surrounding somatic ciliature. The presence of this inconspicuous organelle, quite novel to the genus, is also detectable in the infraciliature where an argentophilic “polar basal granule-complex” appears exactly at the posterior pole of the body. The diagnosis of the genus Tetrahymena is expanded to embrace species with such a caudal appendage.

Notes: SUMMARY. Ciliates referable to Tetrahymena limacis have been found in two native terrestrial pulmonates, Monadenia fidelis (Helicidae) and Prophysaon andersoni (Arionidae), collected in Oregon. The number of complete primary meridians in ciliates in natural infections in M. fidelis has been observed to range from 26 to 32, and the number in ciliates in P. andersoni has been observed to range from 37 to 41. T. limacis from the European Deroceras reticulatum (Limacidae) has shown a range of 32 to 40 meridians. From 20 ciliates pipetted from a single natural infection in M. fidelis into either 1% (w/v) yeast extract (with antibiotics) or an infusion of digestive gland tissue, 16 clones were established successfully. The range in the number of meridians in these cultured ciliates was 24 to 29; eight clones showed a range of 24 to 28. Sixteen clones established in the same way from ciliates taken from P. andersoni showed a range of 26 to 32 meridians; ten clones had a range of 27 to 31. The range in the number of meridians observed in earlier studies of 28 clones established from ciliates from two natural infections in D. reticulatum was 25 to 32.To determine whether the ciliates from the native pulmonates have a strong host specificity, 50 D. reticulatum were exposed for 10 days to a clone derived from M. fidelis, and 50 were exposed to a clone from P. andersoni. For comparative purposes, 50 slugs were exposed to a clone derived from D. reticulatum. An additional 50 slugs were maintained in a control group. Ten days after the end of the period of exposure, all of the surviving controls (47) and 25 of the slugs in each group exposed to ciliates were examined for infections. The remainder of the surviving slugs in each group were examined 20 days after the period of exposure. Successful experimental infections were noted in each of the groups of slugs exposed to the three clones, and the ciliates in the infections were typical of the parasitic phase of T. limacis. None of the slugs in the control group were infected. Ten days after the period of exposure, the range in the number of complete primary meridians noted in the experimental infections, taken as a whole, by ciliates of the clones from M. fidelis, P. andersoni, and D. reticulatum were, respectively, 26 to 33, 26 to 37, and 29 to 37. The ranges for ciliates in infections by these same clones 20 days alter the period of exposure were 26 to 33, 29 to 37, and 28 to 36. Incomplete rows, up to five in number, occurred in ciliates in experimental infections by each of the clones, but the addition of the number of incomplete meridians to the number of complete meridians did not influence the maximums, except in the case of some infections by the clone from M. fidelis in which a few ciliates showed a total of 34 meridians. It appears that although T. limacis from the native pulmonates will readily infect D. reticulatum, the ciliates from P. andersoni do not attain, at least under the conditions of the experiments which have been conducted, a number of rows exceeding the minimum number of 37 noted in natural infections in P. andersoni.

Notes: SUMMARY. The effect of surface-active agents on the permeability, survival, and pseudopod formation of the rhizopod, Pelomyxa carolinensis, was studied. Surfactants increased the rate of uptake of Na22 in almost all instances. Tweens which lower surface tension, stimulated or caused pseudopod formation; Tween 80 was the least toxic. The fatty acid component as well as the hydrophile-lipophile balance of the surfactant may influence the rate.

Notes: SUMMARY. A small ameba found both in rocky tide pools and tide washed sand is described. It is widely distributed, having been collected in both Pacific and Gulf of Mexico waters. The ameba extends clear, conical pseudopods which wave prior to retraction. It is presented as Vexillifera telmathalassa n. sp., in the Family Mayorellidae, Order Amoebida.

Notes: SUMMARY. At any given temperature level, the rate of oxygen poisoning increases proportionally with an increase in oxygen tension. But the toxicity of oxygen does not bear a proportional relationship to temperature. At a constant low tension, it is more toxic at low temperatures than at high ones and, at a constant high tension, it is less toxic at low temperatures than at high ones.

Notes: SUMMARY. Washed intact cell preparations of T. vaginalis oxidize pyruvate and malate. They are unable to utilize other intermediates of the Krebs cycle. Homogenates of these cells show the same pattern of enzymatic dehydrogenase activity toward the Krebs cycle organic acids. Attempts to inhibit pyruvate oxidation with such Krebs cycle blocking agents as malonate, arsenite, parapyruvate, and fluoroacetate were unsuccessful.Isotopic tracer studies with 2-C14 pyruvate showed that although several, as yet unidentified, compounds incorporated activity during the course of pyruvate metabolism, none of these labeled compounds corresponded to any of the Krebs cycle intermediates.It is concluded that the Krebs cycle is not the pathway for the oxidation of pyruvate in T. vaginalis.

Notes: SUMMARY. Chromosome behavior of strains WH-6, and WH-14 mating types I and II respectively of variety 1, of T. pyriformis was studied during conjugation. Meiosis takes place during the first two prezygotic divisions. The chromosomes are at late pachytene-early diplotene during the maximum elongation of the crescent in prophase of the first micronuclear division. As the crescent shortens, five bivalent chromosomes are readily recognized. Five dyads go to each pole at the end of the first division. Following a brief interphase the second meiotic division results in four micronuclear products, each with five chromosomes. Three of these products disintegrate; the fourth undergoes mitosis resulting in two pronuclei each with five chromosomes. Following a reciprocal interchange of the migratory pronuclei between the two conjugants, the synkaryon of each is formed just anterior to the macronucleus. The diploid number of ten chromosomes has been counted at the first division of the synkaryon.

Notes: SUMMARY. Isolated Blepharisma undulans were studied for the following: (1) fission rate, (2) mating behavior, (3) giant formation, (4) effects of daily transections. The organisms were maintained at 22°C. and isolated daily for 60 days. Fission rate varied from two divisions a day to one in 29 days. The major factor producing the variation appeared to be the type or amount of food. Frequency of conjugation also varied greatly. Daughters of a single organism will mate within 24 hours after division. Conjugation followed by one division, re-isolation, then conjugation within 24 hours following a second division occurred within a 5 day period. Giants were produced within 3 days by feeding with Khawkinea, Chilomonas and Paramecium. Paramecium alone did not produce giants. Exposure to 10−m, 10−4M colchicine did not accelerate this process.Daily transections into approximately equal halves were made. The anterior halves containing the mouth membranelles were followed. Fission rate was not affected by cutting. A progressive decrease in size occurred. All ultimately lysed, most on the 7th day. If cutting was suspended on any day, recovery and fission followed. If cutting was re-instituted, lysis would again occur on or about the 7th day. Daily amputation of the posterior tip for 2 weeks did not affect either size, fission rate, or longevity.

Notes: SUMMARY. Frontonia depressa (Stokes) Penard is an edaphic species characterized by formation of cysts. There is no dedifferentiation of the ciliate when encysted, and all organelles, except the body cilia and buccal apparatus, are clearly visible. Excystment is dependent upon the building up of hydrostatic pressure by the contractile vacuole. Activation is not always followed by excystment, which takes some hours.

Notes: SUMMARY. As part of an extended series of experiments, various combinations of primaquine-pyrimethamine were tested against pigeons infected with Plasmodium relictum.(a) Rapid clearance of blood forms was observed, although each component had been reduced to one-half of its previously established MED (minimal effective dose) for such clearance when administered alone.(b) Primaquine-pyrimethamine was followed by unprecedented delays in relapse after drug withdrawal. Such delays had not been elicited in any previous experiments in the series, employing each component alone, or chloroquine alone, or primaquine-chloroquine combinations, or pamaquine-plasmocid-chloroquine (Premaline N).

Notes: Some cultures of Tetrahymena pyriformis, strain HS, are amicronucleate; other cultures bearing the same designation are micronucleate. Investigation in cooperation with several workers indicates that the amicronucleate HS cultures are the same as the original. To avoid further confusion, we suggest that micronucleate HS cultures be designated “HSM” in the future.

Notes: A new species of naked Dinophyceae is described and the culture medium for its continued growth denned. The species is distinctive in having a posteriorly placed girdle, characteristic of the genus Katodinium (Fott, 1957), and in possessing a counterclockwise loop of the sulcus about the apex.

Notes: Vorticellas were maintained on Bacillus cereus in a medium composed of unbuffered Proteose-Peptone, Cero-phyl, and the filtrate from boiled wheat kernels. Vorticella-free aliquots of culture medium were analyzed at critical intervals, beginning immediately before encystment and until re-encystment. Control aliquots changed insignificantly; significant changes were detected in the experimental cultures. Osmolality increased from 14 to 18 milliosmols/1, Na+ stayed in the range 2 to 3 milliequivalents/1, K+ decreased slightly below the initial value of 5 mEq/1, Ca++ decreased from 5.7 to 4 mg.%, CI fluctuated slightly down and up from 112 mg.% during the initial 8 hr., then down to 〈 104 mg.%, phosphate decreased steeply from 14 to 〈 0.6 mg.%, pH increased from 6.7 to 8.5.The results indicate that suboptimal levels of K+ Ca++ and phosphate impose upon V. microstoma a physiological stress which leads to encystment. The role played by Na+ and CI- was not clear. Osmolality was a major factor in excystment but not in encystment.

Notes: Two species of trypanosomatid flagellates: Critkidia flexonema from Gerris remigis at Ames, Iowa, and Leptomonas collosoma from Gerris dissortis at St. Paul, Minnesota, were isolated in pure culture and are described as new species. Blastocrithidia gerridis, which differs irorn bath of the new species in possessing an undulating membrane, failed to establish itself in culture.

Notes: The literature on the coccidia of the coypu Myo- castor coypus Mol is reviewed. Four species of Eimeria have been described in these animals: E. seideli, E. myopotami, E. pellucida and E. coypi. The description of E. coypi is similar to E. myopotami in every respect, except for a little variation in size of the sporocyst It is therefore proposed to consider this species synonymous with E. myopotami, Two new species of Eimeria, E. myocastori sp. now and E. nutriae sp. nov. are now described from the coypu, naturalised n England in England.

Notes: The following types of transfauntions were made: from nymphs is an early stage of their molting period to nymphs 1-50 days before ecdysis and vice versa; from recently molted nymphs to nymphs in all stages of the molting period and vicve versa. In such transfaunated half or more of the protozoa in a donor host were transferred to a recipient host. The recipient hosts wee defaunated with oxygen by subjecting them to 60 psi for 2 hours, twice the minimum time necessary to kill all their protozoa. Transfaunations were made 24 hours after defaunation.The sexual cycles, as a result of these transfaunation experiments, in addition to being prevented altogether in several genera, were modified principally in two ways: they were shortened to less than half the time required under natural conditions; they were lengthened, in some genera, from two days to over two months. Whether shorteing or lengthening occurs depends on the type of host used in the experiment. And the factor in the host that is responsible for the modifications is the ecdysone titer; transfaunation from a lower to higher to a lower titer, in general, serves to lengthen it.

Notes: An accurate description of Cyclidium glaucoma O.F.M., 1786, is presented. Fixed specimens were treated with the Chatton-Lwoff silver impregnation technique and the standard Feulgen nucleal reaction. Living material was examined by phase microscopy. Components of the infraciliature have been given special attention, particularly in the buccal area. In brief consideration of the systematic status of this species emphasis is placed upon the close relationship of the pleuronematine and tetrahymenine groups of hymenostome ciliates. Comparisons on structures found in C. glaucoma with corresponding structures in species belonging to quite closely related families are made, and the fundamental nature of the infraciliary tetrahymenal buccal apparatus and the polar basal granule-complex is discussed.

Notes: 3-Amino-l,2,4-triazole (AT) inhibits the multiplication and pigment synthesis of several photosynthetic pro-tists, Ochromonas danica, 0. malhamensis, Euglena gracilis and Rhodopseudomonas palustris; it also inhibits the catalase activity of beef liver and O. malhamensis. Fe++, Fe+++ or lecithin annul the inhibition by AT of multiplication and pigment synthesis in O. danica. Chelation of iron is suggested as the main action of AT on Odanica,

Notes: Rates of penetration of sodium (Na24) and potassium (K/12) into several strains of Chlamydomonas, a flagellated unicellular alga, were studied. Sodium was taken up to a negligible extent by normal, motile cells. Potassium was taken up readily by normal cells and by mutant strains with impaired locomotion. Normal cells tended, during the first hour, to reach equilibrium most rapidly, involving the exchange of TS-of the cellular K. Flagella-less cells approached equilibrium more slowly, involving the exchange of 79′yc of the K. Paralyzed cells gave intermediate values. These results suggest that motile cells may immobilize larger amounts of K than do those with impaired motility.

Notes: Ultrathin sections of Sarcocystis miescheriana were studied in the electron microscope. The banana-shaped body of the parasite shows a polar ring with a conoid at the anterior conical pole similar to that of S. tenella. Twenty-two fine fibrils arise from the polar ring passing radially in the pellicle. The anterior third of the cell is filled with sarconemes converging in the conoid. Behind their ends in the center of the cell large osmiophilic central granules can be seen. A large nucleus in the posterior third with a double membrane contains small chromatin granules situated peripherally. Around the nucleus and in the posterior part of the body numerous small vacuoles with osmiophilic walls, as well as mitochondria are observed. The pellicle consists of 2 layers. On the control preparations cytochemical reactions on ribonucleic acid, deoxyribonucleic acid, polysaccharides, glycogen, volutin and fats were performed. The surface of the cyst is covered by a thin layer showing a honey-comb structure giving rise to a great amount of parallel finger-like villi surrounding the cyst on all sides. The villi contain many very fine double-fibrils ending at the bases of villi in the finely granulated plasmatic interior cyst wall which forms also the septa of compartments. The functions of the observed organelles and structures are discussed.