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: 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: 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: 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.

Notes: A breeding analysis of a wild strain (Indian Lake 12) of variety 1, Tetrahymena pyriformis, discloses recessive lethal alleles at two independently assorting loci. Conclusions concerning the cytogenetic behavior of this species have been verified through the scoring of a large number of offspring segregating the lethals. In particular, cytogamy does not occur in these strains with a frequency higher than 2%. if indeed it occurs at all. The finding of lethal heterozygosity in a wild strain suggests that close inbreeding usually does not take place in nature and supports the conclusion that variety 1 of T. pyriformis is an outbreeding species.

Notes: The flagella of Lophomonas striata are arranged in circular rows in a tuft-like structure. Each one is continuous with a basal body located in the anterior region of the calyx. Each flagellum is limited by the surface membrane and is composed of nine double peripheral filaments and two central ones. The former continue below the surface and make up a large part of each basal body. Below and parallel to the calyx membrane are two layers of fibrils which appear to connect the basal bodies; the first is just below (250 m/x) the surface, the other is attached to the proximal ends of the basal bodies. Extending from the latter is a delicate network of fibers which gradually disappears from view as it continues in the direction of the nucleus. The calyx membrane appears continuous at the level of the basal bodies; however, below this point it seems to be made up of a series of discrete longitudinally arid obliquely arranged lamina or plates, a condition which permits direct continuity of the cytoplasm within and without the calyx. The body of Lophomonas striata is highly as well as tightly folded in its longitudinal axis and the striations or rods are clearly located on its surface; it is suggested that these are held in place by an agglutination reaction. The rods appear to divide by transverse fission and their fine structure resembles closely that reported for certain bacteria; in fact, because of this, we think they should thus be considered.

Notes: The free and bound amino acids of 3 strains of Tetrahymena pyriformis (variety 6) have been identified by filter paper chromatography. Twenty bound amino acids were qualitatively and quantitatively alike in each strain. The same 17 free amino acids were identified in all 3 strains; however, quantitative variations among the cultures were noted. Strain 002. an F1 progeny clone obtained from a cross between strains EU 6000 and EU 6001, exhibited a combination of parental characteristics. The F1 organisms resembled one parental strain, EU 6000, in the ratio of free arginine to alanine, and the other parental strain, EU 6001, in the ratio of free isoleucine to leucine. The possible genetic significance of these results is noted, and the value of chromatographic analysis as an aid to genetic study is discussed.

Notes: Nosema lepiduri n. sp. parasitic in Lepidurus apus L. is described. The microsporidian invades the connective tissue cells of carapace, head and legs of the host crustacean. The developmental cycle and cytology of the organism were studied. The spores stained by McManus method show a small polar cap located at the more attenuated pole, a structure not hitherto reported. It is different from the polar granule which is commonly present in microsporidian spores. The polar cap stainable by McManus method is probably present in the spores of all Microsporidia, though its chemical nature is unknown.

Notes: Eimeria wenrichi n. sp., Isospora mcdowelli n. sp. and Caryospora microti n. sp. are described from the cecal contents of the meadow mouse, Microtus pennsylvanicus, in Pennsylvania. C. microti is the first member of the genus to be reported from mammals.

Notes: In the laboratories of the agip mineraria a new apparatus has been developed which, utilizing reflected energy collected by several groups of seismometers, provides on a single trace an indication of the total energy level. This indication is controled in time according to an exponential characteristic, thus compensating for the attenuation which is effected in the subsurface. The apparatus enables indications of successive energy levels to be obtained for different shots, thus furnishing a time section even during the routine field work.

Notes: The factors affecting the response of a velocity-sensitive well geophone are discussed and it is shown that the geophone movement in response to a seismic pulse is primarily due to the pressure difference between its ends. Several practical examples are calculated to show that the first arrival waveform recorded by a geophone depends on the distance from an interface and that these changes in recorded waveform may give errors of up to 3 msec in well-velocity surveys. These errors may be minimised by using pressure geophones or by avoiding measurements at geological interfaces.

Notes: Surface charges in seismic refraction work in the sand dunes of the Sahara have been necessitated by the many problems involved in shot hole driving. These include lost circulation, unconsolidated surface sands and gravels, caving, poor shot efficiency etc.Tests were conducted in September 1958 in an attempt to evaluate some of the problems involved in surface shooting. This method is complicated by the large number of variables, 8 major ones, influencing the shot pattern.It is difficult to evaluate each of such a large number of variables by an exhaustive and systematic test procedure due to the prohibitive number of shots that this would involve. However, two series of tests contributed greatly to an understanding of the problem, although they left some points to be cleared up.Firstly shots were fired using small charges (less than 25 kg). These gave interesting results, however, they are not applicable to the heavy charges currently in use (500-1500 kg). These results refer primarily to the use of suspended charges which gave superior results to those obtained from surface charges layed on the ground. They also tend to indicate the influence of the weight of the charge. This is manifested by a saturation in seismic energy, as the size of the charge increases.The results obtained from the shooting (200 kg) of several individual charges are not as pronounced. The following conclusions are drawn:Nitrate explosives, in current use in the Sahara for several years, give good results in refraction.– The use of suspended shots does not result in sufficient gain in energy over the ground shots to justify their more complicated utilization: preparation, partial destruction of supports, safety etc. Hence further shooting of suspended charges has been abandoned.– The detonation of individual charges by use of primacord layed parallel to the line, in preference to simultaneous electrical detonation, gave superior results from the energy point of view (especially for high frequency arrivals) and simplified lay-out procedures. Hence this method was adopted.– As for the small charges the relation between seismic energy and weight of the individual charges shows a saturation effect which is less pronounced.–The distance between the individual charges appears to be the most important variable. The relation, seismic energy-distance between charges, indicates an increase in a linear manner for distances of 5 to 20 meters. It would appear as though the beneficial effect for greater distances diminishes beyond this point.Finally, it would appear as though it would be preferable for a given overall charge to reduce the weight of the individual charges and increase the distance between the individual charges. Obviously this rule has certain practical and economic limits. If the cost of the unit of seismic energy is evaluated it is preferable to utilize large distances between charges (20 m) but also relatively large individual charges (about 25 kg).The testing program was followed by nine months of surveying in different types of terrain. The parameters were etablished from the results of the testing program.Economically the following conclusions may be drawn: The average explosives consumption increased from 1000 kg for the shot–hole shots to 1500 kg for the surface shots. This increase, costwise, represents almost exactly the cost of shot hole drilling at the present price of explosives. Efforts are being made to have the price of explosives reduced and should this realize the net result will be a definite cost advantage in favor of surface shooting.In addition, the introduction of magnetic recording in refraction work to the Sahara in 1959 appears to indicate a substantial reduction in the size of the charges needed, hence, a further advantage to surface shooting.

Notes: The paper discusses the variations of Elevation Correction Factors (E.C.F.) across various stratigraphical and structural occurrences with particular reference to the dipping bed, fault and horst. Graphs are prepared giving E.C.F. variations for various angles of dip and a method is suggested for application in the field. Errors in the linear variation that is commonly used for small angles of dip are discussed.The second part of the paper consists of the application to interpretation of (I) Change of gravity dip and (2) The gravity inversion. It is shown how from a gravity map the dip, position of outcrop and thickness of a dipping bed can be determined. The last part shows how anticlines can give rise to negative anomalies and that in the direction of dip similar structures can at one point have no surface expression and afterwards invert to positive anomalies. The danger of attempting to predict the size of structures in such areas is emphasised.

Notes: When gravimetric prospecting is concerned with a region featuring broken relief the calculation of topographical corrections becomes vitally important, for these rectify apparent anomalies completely. It is essential that they should be calculated as exactly as possible. By the classic method this takes an extremely long time and may in the long run involve an outlay actually higher than that expended on operations on the terrain.It has thus been felt necessary to seek methods which would speed up calculation, and, bearing that in mind, the use of a polar integrator has been envisaged. With this the contour lines of a map can be followed between two fixed radii, the pole corresponding to the location of the position. Two integrator roulettes will give the values of the first two terms of the expansion in terms of the quotient of the height divided by the distance, the second of the terms resulting from the curvature of the earth. Unless there are escarpments very close to the position, the use of these two terms will be sufficient.Polar integration will deal successively with different contour lines and a subsidiary graph will be plotted, giving the value of each of the integrals in terms of the height. By means of this subsidiary graph the values of the corrections will be obtained with a planimeter and a moment integrator. It is envisaged that the same operation could be repeated in the case of two maps with different scales, for instance, 1–20,000 and 1–200,000 the effect of the areas in the immediate neighbourhood of the position being taken into account by the observer. It is hoped that in this way the calculation of topographical corrections will be made quicker, more exact and less laborious.

Notes: The problems connected with reflexion surveys in areas of rough topography consist of choosing proper equipment and of making careful near-surface corrections. This paper illustrates some solutions to these problems that have been adopted in a survey which has recently started in a hily coastal area, in Southern Italy.As the area is characterized by a youthful and very actively eroded topography of Post-Miocene clays and litoral clastic sediments, both rotary and percussion drilling were necessary whilst all the seismic equipment had to be light to allow straight lines to be shot as far as possible. Details are given of the truckmounted, light equipment which has been designed for this special purpose.In connection with the youthful topography of the area being surveyed, the criteria for the proper computation of the near-surface corrections is discussed. The great differences in elevation, combined with variations in the surface and near-surface materials, necessitated a careful analysis before deciding the thickness of the correction zone. The results are shown of the preliminary tests carried out in order to determine the average thickness of the low-velocity zone. The solution adopted for drawing the reference surface determining the base of the correction zone for the whole of the area is subseqently explained.Reference datum is drawn so as to follow gently, and with segments of constant slopes, the general features of the rough topographic relief at a depth ranging from 30 to 60 metres from the surface. Criteria for the routine checking of velocity variations in the correction zone are illustrated. Such checks are based on both uphole time analyses and refraction “first breaks” plots, with deeper shot holes at constant intervals.Unsatisfactory results necessitate longer spreads for “low velocity tests” and uphole shooting from deeper holes and the reference datum is deepened for the particular area where this becomes necessary.The final cross-sections are shown and although, as yet, no deep holes, are available to check the seismic data, the general appearance of the cross-sections seems to indicate that subsurface data are free from the influence of topography and of the velocities in the near-surface formations.

Notes: The paper describes the determination of the chlorine content of deep ground water by means of the direct resistivity method using the Wenner electrode configuration. The purpose was to investigate the distribution of salinity in the brackish waters within a permeable sand of thickness 250 metres and which forms the deeper subsoil of the Ysselmeer areas.Such a knowledge is of great value, firstly because the seepage of salt water into the proposed deep “polders” may reduce the crop yield, and secondly because it allows areas, where potable waters may occur, to be delineated.To test the method, measurements were made near existing boreholes which extended to a depth of 350 metres. From these borings water samples from various depths were collected and it was found that the resistivity pl of the porewater was closely related to their chlorine content. The resistivity p of the saturated sand was determined from the geo-electrical measurements. It was found that the resistivity p was given by p= 4, 5 pl. From this relation, which is independent of the salinity, the chlorine content of the porewater could be estimated. These results are in close agreement with those of other observers. In the area p varied from 1 to 200 ohmmetres corresponding to a chlorine content changing from 12.000 to 15 mg per litre.The method was adapted for working over water. Each of fourteen insulated conductors in a special cable terminated in an electrode, and these electrodes were spaced along the cable so that nine different Wenner spacings could be selected. The electrode separations varied from 44 metres up to 306 metres.

Notes: The authors develop an optimum filtering theory for seismic reflection recording. A criterion of record improvement is applied to a mathematical model consisting of a set of wavelets superimposed on a random noise backgruond. This leads to the design of electrical filters and geophone and shot-hole patterns with optimum filtering characteristics.