ALBERT

Notes: SYNOPSIS. A method is described which permits the recovery of a high yield of undegraded DNA from Acanthamoeba castellanii. The DNA of A. castellanii is comprised of 2 species: the buoyant density of the major component is 1.720 and of the minor component, 1.693. The renaturation characteristics of the minor component suggest that it is of mitochondrial origin. Two components are also present in the DNA of A. palestinensis, A. polyphaga and A. astronyxis. The buoyant densities of major and minor components differ between species.

Notes: SYNOPSIS. The peritrichs have taught naturalists, biologists, zoologists, and other kinds of scientists many of their secrets. Consequently, we know many details regarding their gross structure, ultrastructure, ecology, and life history. Their sexual phenomena are rather clearly understood. While general agreement has been attained as regards the forementioned topics, the taxonomic position of peritrichs is still vigorously debated. In this address representative examples of advances in our knowledge of peritrichs will be reviewed … representative instead of all-inclusive examples. A plea for the restoration of peritrichs to a taxonomic position above spirotrichs will be made. The Society's members will be assured that all protozoologists will have the opportunity to help design a completely International Commission on Protozoology in the International Union of Biological Sciences and they will be assured that such a Commission can and should be planned at the 1969 International Conference in Leningrad.

Notes: SYNOPSIS. Eleven of 14 hypocholesteremic drugs inhibited aerobic respiration of the phytoflagellate Ochromonas danica. Lecithin and unsaturated fatty acids annulled the inhibition of respiration by triparanol. Saturated fatty acids, squalene, cholesterol and a mixture of amino acids, purines, and water-soluble vitamins were inactive. Unsaturated fatty acids only annul the triparanol inhibition if preincubated or added simultaneously with triparanol. Evidence is presented suggesting that triparanol and oleic acid form a complex or micelle; presumably in this form the triparanol no longer inhibits aerobic respiration.

Notes: SYNOPSIS. At 850 ppm apholate [2,2,4,4,6,6-hexakis (1-aziridinyl)-2,2,4,4,6,6-hexahydro-1,3,5,2,4,6-triazatriphosphorine], an insect chemosterilant, reduced growth of the marine flagellate Tetraselmis subcordiformis by 50% in 21 days. Mean cell volume more sensitively indicated cellular response at low apholate concentrations than cell number or biomass. Two other aziridinyl chemosterilants tested were 12 and 120 X more toxic than apholate—values agreeing with those reported for some estuarine animals. Apholate acted directly upon the organisms rather than indirectly on the experimental medium since comparatively small molar additions of orotic acid, adenine, guanine, and thymine to apholate-poisoned cultures annulled the growth inhibition. Determining the mode of action of aziridinyl chemosterilants by activity annulment is discussed.

Notes: SYNOPSIS. (P32O4) is rapidly incorporated into DNA of resting cells of Euglena. This incorporation is strongly inhibited by bleaching doses of ultraviolet light. Photoreactivation of the bleaching effect does not immediately restore the rate of P32 incorporation into DNA. It is indicated that this metabolically active DNA is not directly associated with control over the development of the plastids.

Notes: SYNOPSIS. Hexokinase was in both soluble and particulate fractions of extracts of Trypanosoma brucei, T. gambiense, T. rhodesiense and T. equiperdum. These enzymes have been purified some 350-fold from crude extracts by sonication, (NH4)2SO4 fractionation, and DEAE Sephadex column chromatography. Purified hexokinases had: A) temperature optimum 45-50 C; B) pH optimum 6.5-7.0; C) Mg++ and ATP requirements; D) inhibition by ADP, p-hydroxymercuribenzoate, glucose-6-phosphate, and competitive inhibition by mannose, glucosamine, N-acetyl-D-glucosamine and xylose; E) ability to phosphorylate glucose, fructose, mannose, 2-deoxy-D-glucose and glucosamine; F) a glucose requirement for stabilization. T. equiperdum hexokinase was inhibited 33% by ADP as compared to 17-20% with brucei group hexokinase, and showed 22% activity when ITP was substituted for ATP in contrast to 35-40% with brucei group hexokinase.

Notes: SYNOPSIS. Conjugation in Paramecium aurelia has been studied in live and sectioned cells and oral development studied following ultraviolet microbeam irradiation. The live cells allow a clear correlation to be made between nuclear behavior and gullet development. The paroral cone lies at the level of the buccal overture. The new oral area develops while the old one is still present, the latter structure being still visible after the conjugants have separated. Sectioned material confirms the fact of cytoplasmic fusion at the level of the paroral cones. It also confirms the appearance of new buccal organelles on the right side of the buccal overture of the pre-existing gullet. Ultraviolet microbeam irradiation of the buccal area shows that the posterior edge of the buccal overture must remain undisturbed for normal development. Irradiation of the anterior edge of the buccal overture also affects development. These results differ from earlier work on fissioning cells. Discussion of these differences leads to the conclusion that the factors controlling stomatogenesis are developmentally regulatory.

Notes: SYNOPSIS. Experiments were designed to examine the nature of the response of Tetrahymena pyriformis to inhibitory levels of L-serine when growing in defined media with carbohydrate as mono-, or polysaccharide. Growth curves indicated that, when a polysaccharide is being utilized, inhibition by serine affects at least 2 different loci. At one locus, inhibition causes a marked increase in the growth lag, at the other a significant decrease in the maximum rate of growth. Since the inhibition was completely reversible by glucose supplementation, it is evident that the initial inhibition, expressed as increased lag time, is specifically related to uptake or metabolism of the polysaccharide, i.e., it precedes glucose in the metabolic sequence. The inhibition expressed as decreased rate of maximum growth appears to be due to interference at some stage in the glycolytic pathway. The results suggest that in metabolizing a polysaccharide, T. pyriformis utilizes 2 mechanisms simultaneously. One involves phagocytic ingestion of molecular dextrin followed by phosphorylytic cleavage whereby the energy of the glycosidic bond is utilized to form glucose-1-phosphate. The 2nd mechanism depends upon elaboration of extracellular hydrolytic enzymes to cleave the polysaccharide to glucose, which enters the glycolytic pathway via glucose-6-phosphate in the usual manner.

Notes: SYNOPSIS. An initial rise in temperature increases the reproductive rate in Blepharisma intermedium; after it reaches the maximum, it gradually declines and finally fission is blocked. Cytochemical investigations made on Blepharisma acclimated to 28 C—the temperature at which the reproductive rate is maximum—show that conditions are optimum for cell division. Requisite quantities of glycogen, basic proteins, unsaturated lipids, enzymes alkaline and acid phosphatases are present. At 38 C the cell metabolism is altered, there is a decrease in the quantity of glycogen reserves, proteins and lipids, the enzyme activity diminishes, the free amino acid pattern changes and cell division is blocked. However, this block is transitory. Upon return to room temperature and when fresh culture medium is added, after a lag of 3 days, the cell metabolism becomes normal and the ciliates resume fission.

Notes: SYNOPSIS. Two electrophoretically distinct forms of glutamate dehydrogenase were found in extracts of Chlamydomonas reinhardi. The slower moving of these was detectable only when the cells were grown organotrophically. The other, more active, enzyme copurified with chloroplasts and was not electrophoretically detectable in extracts of organotrophically grown cultures of the y-2 mutant strain; this absence was not apparent in wild type or in the mutant strain y-1. Both forms of the enzyme were cofactor non-specific.

Notes: SYNOPSIS. Scanning electron microscopy was used to reveal detailed surface structure of 4 septate (Gregarina cuneata, G. steini, G. rhyparobiae, Pileocephalus blaberae) and one aseptate species (Nematocystis elmassiani) of eugregarines. The epicyte of all these gregarines is differentiated into a system of regular longitudinal folds. In the septate species these folds undulate so that these organisms glide along. The undulatory pattern is absent from Nematocystis, which does not glide. The theories and the mechanism of gregarine gliding are discussed.

Notes: SYNOPSIS. The free form of Ichtyobodo necator is typically quadrangular, with rounded corners, and flattened dorso-ventrally. Its dorsal surface is strongly convex and its ventral surface somewhat concave. A longitudinal groove traverses the posterior 2/3 of the ventral surface near its right margin. The part of the organism anterior to the groove is rather thick; that containing the depression thins out progressively toward the posterior end. Most of the organelles are in the major part of the cytoplasm to the left of the groove. Anteriorly this depression continues into a rather short canal. Two (4 in predivision stages) flagella originate near the anterior end of the canal, from which they run posteriorly. The cytostome is also near the anterior part of the canal. The cytostome, canal, and cell membrane are reinforced by microtubules. The chondriome, undoubtedly represented by a single very elongated mitochondrion, contains numerous dilated areas rich in deoxyribonucleic acid.The fixed form of the flagellate is highly modified. Its anterior part becomes attached to the host cell by forming a plate. A type of sucking organelle that contains the cytostome forms from the plate and penetrates the host cell. I. necator belongs in the family Bodonidae. RESUME La forme libre d'Ichtyobodo necator est quadrangulaire avec des angles arrondis, et présente un aplatissement dorsoventral. Sa surface dorsale est fortement convexe et sa surface ventrale légèrement concave. Une gouttiére longitudinale traverse les 2/3 postérieurs de la face ventrale sur le bord droit. La région cellulaire antérieure à, la gouttiére est plus épaisse que celle qui contient la dépression et s'amincit progressivement vers la partie terminale. La plupart des organites cellulaires occupent la partie gauche de la cellule. Dans la région antérieure la gouttiére se prolonge par un canal assez court. Deux (quatre dans les stades de prédivision) flagelles partent de ce canal et se dirigent vers la région postérieure. Le cytostome est également localisé près de la région antérieure du canal. Le cytostome, le canal et la membrane cellulaire sont jouxtés de microtubules. Le chondriome, sans doute représenté par une seule mitochondrie très allongée, présente de nombreuses dilatations riches en acide désoxyribonucléique.La forme fixée du flagellé est très modifiée. Sa partie antérieure adhère à la cellule hǒte par l'intermédiaire d'un plateau. Une sorte de suçoir, qui contient le cytostome, se forme à partir de ce plateau et pénètre dans la cellule hǒte. Ichtyobodo necator appartient à la famille des Bodonidae.

Notes: SYNOPSIS. Conjugation in Stentor coeruleus was investigated, using a standardized culture technic which yielded large numbers of mating pairs within a single culture. Spontaneous bursts of selfing occurred during a definite interval in the development of a culture. Structurally distinct preconjugator cells appeared immediately before as well as during the initial stages of a burst of conjugation. Mating pairs were formed by the union of 2 preconjugators.Mixing 8 stocks in all possible combinations of pairs and observing their subsequent response revealed they were separable into 2 complementary mating types. The majority of mating pairs formed in mixtures of stocks consisted of individuals of different mating types.It is suggested that control of mating types in the ciliate order Heterotrichida may be of a somewhat different nature from that found in other ciliates.

Notes: SYNOPSIS. Myxin (1-hydroxy-6-methoxy-phenazine-5,10-dioxide), a wide spectrum antibiotic, inhibits chloroplast replication in Euglena gracilis strain Z at concentrations which have no effect upon growth or survival. Myxin also inhibits the synthesis of chlorophyll when etiolated Euglena are illuminated in resting medium. By analogy with its action on bacteria, it is suggested that myxin may cause selective inhibition of chloroplast nucleic acid synthesis.

Notes: SYNOPSIS. Plasmodium balli sp. nov. is described from Anolis lionotus and A. poecilopus of central Panama.Large, elongate gametocytes and segmenters containing up to 100 merozoites are produced by P. balli. Proerythrocytes and normoblasts are more commonly parasitized than erythrocytes. Pigment is uncommon, but when present consists of a minute dot. Hypertrophy, distortion and lysis of host cell nuclei may result from parasitization of immature blood cells by gametocytes, while enucleated host cells are common.

Notes: SYNOPSIS. Platyamoeba stenopodia n. g., n. sp., isolated from a lake in Alabama, is an amoeba with flattened form, usually more than 2.5 × as long as broad, the anterior half hyaline and the posterior half granular, with a single vesiculate nucleus at the posterior edge of the hyaline region. It forms a transitory floating stage with slender, hyaline pseudopods. Its cyst is spherical, uninucleate, with a smooth inner wall and a thinner, closely applied outer wall, which is often slightly wrinkled. Length of locomotive amoeba 15–36 μ diameter of cyst 7–11.5 μ Reproduction by binary fission with mesomitotic nuclear division, the nuclear membrane disappearing in prophase. The genus Platyamoeba is erected for amoebae including this organism; the type species is P. placida.

Notes: SYNOPSIS. A new species of Eimeria is described from the redeared turtle, Pseudemys scripta elegans. The sporulated oocysts are ovoid to broadly ellipsoid, averaging 24.2 by 13.7 μ. A micropyle is present, rising slightly above the normal curvature of the wall. An oocyst residuum and polar body are absent. The sporocyst residuum is a compact mass of granules varying in number and size; less frequently the granules are loosely scattered in the central portion of the sporocyst. Rarely. the residuum appears bound by a thin membrane. The sporocysts are 11 by 5.9 μ.

Notes: SYNOPSIS. Babesiosoma ophicephali n. sp. (Babesiidae; Haemosporidia), from the red blood cells of the freshwater teleost fish Ophicephalus punctatus Bloch, collected from suburbs of Calcutta, is described. Giemsa-stained films of blood from the caudal region of 20 fishes were examined, and 2 fishes were found to be infected. The genus Babesiosoma is described for the first time in India. The systematic position of the parasite is discussed in detail.

Notes: SYNOPSIS. Data concerning the DNA and RNA content of 3 Trypanosoma species (T. equiperdum, T. gambiense and T. cruzi) are given. Kinetoplastic DNA was fractionated and separated from nuclear DNA by ultracentrifugation in a CS2SO4 gradient after complexation by mercury or silver ions. Buoyant densities in the analytic ultracentrifuge, base composition and melting point of these DNA's were studied.

Notes: SYNOPSIS. Thru the application of technics of serology, cultivation in acid and basic media, host specificity and reaction in foreign hosts it became possible to characterize 10 species of Crithidia and to assign names to 5 of those previously undesignated. Despite a loose host specificity under experimental conditions it was found that each isolate from a different insect host was a different species.

Notes: SYNOPSIS. The nonpathogenic flagellate from the cecum of fowl, hitherto known as Histomonas wenrichi Lund, is an actively ameboid organism equipped with 4 flagella. Three of the flagella, subequal in length, are applied to one another for a short distance anterior to their origin in the kinetosomal complex and typically terminate in knob-like expansions; the 4th flagellum originates independently of the others and ends in a fine filament. A short, wide pelta is joined to the anterior part of the broad, spatulate axostylar capitulum applied to the left-ventral surface of the ellipsoidal, spheroidal, or ovoidal nucleus. Posterior to the nucleus the capitulum narrows into a slender axostylar trunk, which does not project beyond the body surface. The parabasal body, associated with a long, stout parabasal filament, is dorsal and to the right of the nucleus. On the basis of the flagellar number, the parasite is placed in a new genus Parahistomonas. A new subfamily, Protrichomonadinae, is created within the appropriately emended trichomonad family Monocercomonadidae for Parahistomonas wenrichi (Lund) comb. nov. as well as for Histomonas meleagridis (Smith) and Protrichomonas legeri (Alexeieff).

Notes: SYNOPSIS. Development of a suitable tissue cell system for the growth of T. cruzi required the production of infective metacyclic trypanosomes and tissues which these forms could infect. Human heart was selected from a range of serially-cultured tissue cell lines as the most suitable for intracellular growth. Most metacyclic forms occurred when the growth medium had an initial pH of 7.2 and the cultures were gassed with 5% CO2/95% air before closure and then incubated at 33 C.During the first 4 days of incubation ∼ 10% of tissue cells in cultures were infected with 1–5 leishmanial forms of T. cruzi. During the next 4 days, the number of infected cells about doubled and many contained 10 or more leishmanias. The effects of drugs were studied on this 2nd 4-day period of incubation. The aminonucleoside of puromycin affected growth of the intracellular but not the extracellular parasites whereas trypacidin had the opposite effect, inhibiting growth of the extracellular but not the intracellular forms. Aminopterin inhibited the growth of both extracellular and intracellular forms. The selective effects of the aminonucleoside of puromycin against intracellular forms might be due to it being metabolized by the host cells to a more active trypanocide.A method for isolating intracellular forms of T. cruzi from the tissue cells is described. Dihydrofolate reductase activity was found in these preparations and in similar preparations of the culture and blood forms. The reductase was sensitive to inhibition by aminopterin and a 2, 4-diaminopyrimidine.

Notes: SYNOPSIS. Tetrahymena pyriformis syngen 1, mating type II, (optimal growth temperature ∼ 37 C) ordinarily dies out in 5-14 days at 0-5 C. Dying cells were lumpy, suggesting membrane damage. By supplying crude soy lecithin, survival at 0-5 C was prolonged (after growth in peptone-yeast-dextrin) to at least 22 weeks. Crude soy sterols or sitosterol or stigmasterol, and antioxidant, e.g., Ionox 330 or ascorbylpalmitate, permitted survival of cells in suspension or in growth media for at least 16-22 weeks. These sterols are known to protect against triparanol toxicity, which suggested that triparanol, which blocks cholesterol synthesis in higher animals, might enhance cold-induced injury. Triparanol was more toxic at 0–5 than at 28 C for cell suspensions and cells in growth medium; this toxicity was annulled by crude soy lecithin or β-sitosterol, the only phytosterol tested. The synthetic medium intended as a control on the crude media became toxic at 0–5 C. Protection against cold damage is discussed as a means of elucidating the role of sterols—especially phytosterols—and other lipids in maintaining the integrity of the ciliate cell membrane.

Notes: SYNOPSIS. The structure and respiration of sporulating Eimeria tenella and E. stiedae oocysts was compared. Oocysts were purified by Clorox digestion and incubated at 29 C. The sporulation events were similar for both species, except for the spindle stage, altho sporulation took longer in E. stiedae. Sporulating oocysts go thru the process with some degree of synchrony.Oocyst respiration was measured polarographically. An early increase in respiratory rate in both species was followed by a depression in rate that correlated with the appearance of the early spindle stage. The rate again increased and then decreased toward a base rate during and after completion of sporulation. E. tenella oocysts incubated in air remained viable 4 times longer than those incubated in nitrogen. E. tenella sporozoites excysted and remained motile in the presence of sodium cyanide. These facts suggest that E. tenella sporozoites are facultative anaerobes.

Notes: SYNOPSIS. The fine structure of Peridinium westii Lemm., an armoured dinoflagellate collected from Lake Tiberias, is reported. Thick cell walls contain plates, pores and tubules, and are surrounded by an external membrane. The cytoplasm is limited by 3 membranes. Nuclei contain numerous chromosomes with a fibrillar organization. The chloroplast envelope consists of 3 membranes; parallel lamellae, each generally comprising 3 thylakoids, are present. Pyrenoids are present in various forms within the chloroplast structure. Trichocysts are found in cells both as elongate dense cores within a membrane-enclosed sac and as striated rods. An eyespot is found in a plastid containing several thylakoids.

Notes: SYNOPSIS. A species of Nosema in the muscles of the North American white shrimp, generally known as Penaeus setiferus but also known as P. fluviatilis, appears identical with type specimens of N. nelsoni Sprague, 1950, in P. aztecus. Its Golgi apparatus, as seen in the sporoblast, is a complex system of cisternae, small vesicles and expanded sacs which plays a major role in spore morphogenesis. It transforms directly into the polaroplast complex, certain membranous investments of the polar filament, the polar sac and perhaps part of the posterior vacuolar system. Probably the polar sac contains the polar cap. The PAS-positive material in both the cap and the filament may be a component of the Golgi complex. This new concept of the Golgi complex supplements our earlier view of spore morphogenesis according to which the polar filament is of nuclear origin. It also reconciles the idea with Vávra's identification of Golgi vesicles associated with the developing polar filament.

Notes: SYNOPSIS. Growth of Crithidia fasciculata, a trypanosomatid flagellate known to contain epinephrine and serotonin, is sensitively inhibited by several adrenergically and serotoninergically reactive drugs such as dichloroisoproterenol, desipramine, and cyproheptidine. The pattern of sensitivity of Crithidia to these drugs is contrasted to the pattern of sensitivity of the ciliate Tetrahymena pyriformis.

Notes: SYNOPSIS. In the culture forms of the elasmobranch trypanosome Trypanosoma raiae is found a prominent cytopharyngeal complex. This consists of a group of 5 or 6 microtubules associated with a deep invagination of the cell membrane which arises from a cytostome near the opening of the flagellar pocket. This structure is a constant feature of the various epimastigote and trypomastigote forms that this flagellate has in culture. Replication of the cytopharyngeal apparatus is completed before cytokinesis.Experiments using ferritin as an electron dense tracer show that endocytosis occurs from the blind ending of the cytopharynx both in the exponential and stationary phases of growth in vitro. Ferritin is transported from the cytopharynx by endocytotic vesicles to large, membrane-bound vacuoles in the posterior region of the cell. Ultrastructural location of non-specific acid phosphatase within these digestive vacuoles and also within the Golgi apparatus is reported.Coated vesicles found in association with the flagellar pocket are another route of uptake of ferritin by T. raiae.

Notes: SYNOPSIS. Rabbit antiserum can transform paramecia from one scrotype to a 2nd antigenic type. Altho homologous antisera made against antigens sharing the same specificity as that of a treated cell are most effective, other sera lacking crossreacting antibodies also can induce transformation. Furthermore, normal serum from unimmunized animals will often have the same effect. A 0-40% ammonium sulfate fraction of serum removes a lethal factor, leaving behind an efficient agent for transformation. The activily of this agent will vary from rabbit to rabbit, and apparently is characteristic of a particular rabbit.

Notes: SYNOPSIS. Paramecium aurelia exposed to antisera prepared against cells of a different surface antigenic type are often induced to transform to a new serotype. One possible explanation is that paramecia that are so affected have antigens related to the ciliary antigens, but not accessible to immobilizing antibodies. It is these secondary antigens that are bound by the antibodies, thereby forcing the cells to alter their pattern of antigen synthesis. Examination of affected paramecia has disclosed that secondary antigens are often present but the specificity of these antigens cannot account for the activity of the antisera. It is therefore proposed that antibodies directed against substances other than the immobilization antigens may induce transformation. Two kinds of antiserum, neither of which contains immobilizing antibodies of any sort, are able to markedly alter the expression of the serotypes. One was obtained by immunizing rabbits with culture fluid in which paramecia had been growing. The 2nd was made by injecting rabbits with normal sera from other rabbits.

Notes: SYNOPSIS. Cells of T. pyriformis GL-C, transferred from a complete axenic medium to a medium lacking amino acids, cease dividing after several hours, and instead begin to undergo oral replacement. This process can be synchronized by a single long 33.8 C treatment. Oral replacement was also observed during stationary phase of normal culture growth in cells of strain GL-C and WH-6 (syngen 1).In strain GL-C the oral replacement primordium is initiated by the appearance of a small number of kinetosomes adjacent to the anterior end of kinety 1, just posterior to the undulating membrane (UM). The UM then loses its cilia and becomes disorganized, and is thus converted into a field of kinetosomes which is broadest near its posterior end. This UM-derived field then becomes joined with the much smaller field which had appeared earlier near the anterior end of kinety 1. As a consequence, the right margin of the UM-derived field becomes continuous with the anterior end of kinety 1, and thus comes to appear as an anterior extension of this kinety. The membranelles and UM of the new oral area differentiate within this composite field. While this is going on, the membranelles of the old oral area are progressively resorbed; these old membranelles always remain spatially separate from the oral replacement primordium.In strain WH-6, the stomatogenic field initially formed adjacent to kinety 1 is substantial, and the role of the UM kinetosomes in stomatogenesis is less obvious than in strain GL-C. The posterior portion of the UM probably contributes to the oral replacement primordium, while the anterior portion is resorbed. In this strain small supernumerary primordia are occasionally seen adjacent to the portion of kinety 2 which is nearest to the posterior region of the UM.It is suggested that the junction between the posterior portion of the UM and the neighboring cortex can serve as an inductive zone for initiation of stomatogenesis, the UM itself having a varying capacity for direct provision of kinetosomes for the stomatogenic field. The flexibility of the stomatogenic site in T. pyriformis is discussed in relation to the apparent restriction of potentialities in peniculine ciliates such as Paramecium.

Notes: SYNOPSIS. Eimeria yukonensis sp. n. is described from the Arctic ground squirrel Spermophilus undulatus. The sporulated oocysts are elongate-ellipsoidal, averaging 24.5 by 13.3 μ. A micropyle is present but an oocyst residuum and polar body are absent. The ovoid sporocysts average 10.9 by 5.9 μ. The sporocyst residuum is ellipsoidal to spheroidal.

Notes: SYNOPSIS. Development of Trypanosoma lewisi in chimaeric mice with and without rat serum supplements was studied in 5 protocols. Chimaeric mice were male and female C3H/An Cum and 1C3F1, [(101/CUM × C3H/An Cum) F1] exposed to 950-1000 R of whole-body X-irradiation. Their hemopoietic systems were replaced with Sprague-Dawley rat bone marrow.Trypanosomes did not develop in any mice not supplemented with rat serum. Ih those chimaeric and normal mice given rat serum the trypanosomes grew and developed large populations, more so in chimaeric than in normal animals.The development of this trypanosome cell in heterologous mice is viewed as mediated principally thru nutritional factors supplied by rat serum with alteration of host-immune status being of lesser importance.

Notes: SYNOPSIS. A Glugea xenoma sectioned and viewed with the electron microscope contained many spores with everting polar filaments. Several details not seen in previous studies of this species were observed. A specialized area with the appareance of a lattice was commonly present near the anterior end of the polaroplast. The external portion of a partially everted polar filament appeared to have about twice the diameter of the part remaining within the spore. No membrane was seen limiting the external surface of the everted portion. The everting filament had pushed thru the polar cap and the adjacent thin area of the spore wall, making the polar cap into a ring. The ring connected the proximal end of the everting filament to the inner spore membrane, thereby anchoring the filament to the spore. The electron density of some of the membranous organelles of the spore was enhanced by the use of ruthenium red.

Notes: SYNOPSIS. Mayorella palestinensis, a small soil amoeba, clumped during active growth in axenic, fluid culture media. Clumping was not associated with starvation (as in the case of cellular slime molds) or with encystation Hartmannella rhysodes was used as a control amoeba which did not clump to the same extent, but otherwise resembled M. palestinensis. Mixtures of both amoebae formed mixed clumps, without subsequent segregation of amoebae in the clumps.Clumping by M. palestinensis was temperature dependent, localized to the surface of the amoeba and required surface conformation. The requirement for a living system could be separated from the surface specificity of M. palestinensis and satisfied with living amoebae that did not clump by themselves, i.e., H. rhysodes, but did clump with dead M. palestinensis.It is proposed that amoeba-to-amoeba adhesion is similar to foreign substrate adhesion, and that M. palestinensis adheres to itself because its surface is more suitable for adhesion than other surfaces present in the culture. A competition for adhesion exists between surfaces so that clumps can be dissociated by providing a foreign surface that is more suitable for adhesion than the surface of the amoeba.

Notes: The study of economic history attempts to reveal the causes of the growing international economic disparity and to identify the strategic factors of economic change. The historical inductive method, analysed economic history in terms of stages of growth.The underlying idea of the concept of stages, found in List, Marx, the German historicists, and revived in a modern form by Rostow, is that every society passes several phases of economic growth, from infancy or primitive stage to maturity or highly industrialised society. However, the essence of stages in different concepts was not uniform, neither was the indispensability of each and everyone of the stages uncontested. Weber, in particular, opposed the monistic approach, and suggested the concept of ‘ideal types’ from which realities are necessary deviations.Marx's contribution to modern growth theory lies in his dynamising of the classical theory through his expanded reproduction function, envisaging both capital and labour, and their qualities, as the strategic factor of growth, rendering possible both a highly industrialised and an equalitarian society, while List's model can be considered the origin of A. G. B. Fisher's and C. Clark's primary, secondary and tertiary sectors. Even in Schumpeter, stages and periodisation of growth can be easily traced, although they are chiefly explained in terms of technology, entrepreneurship and business cycles.Among the modern growth theorists, mainly Rostow revived the concept of stages and the notion of a ‘threshold’ rate of investment as the strategic factor of expanded reproduction and development, while W. G. Hoffmann with his shift from consumer- to capital-goods industries again calls to life Marxian transition as well as the three-sectors concept. Like his predecessors, List with industrialisation and Marx with the capitalist stage, also Rostow is mainly preoccupied with one particular, ‘take-off’ stage. Despite its flaws, Rostow's concept has become a useful tool of historical and positive analysis as well as a framework for normative models fervently looking for strategic factors of change, and some lessons of economic history. It also brought to the fore the rather paradoxical recent development in the economic camp, with ‘new economic historians’ employing purely quantitative methods of research, and growth theorists looking for help (and desirable quantification) to qualitative variables to explain past and present growth trends and to shape adequate growth models.

Notes: This paper provides a brief chronological summary of the main texts concerning education of leading economists from Adam Smith to Pigou. It shows that the classical economists have clearly and almost unanimously recognized education as (1) an investment in human beings; (2) a consumer durable par excellence; (3) a political good in that it preserves law and order; (4) a social good in that it contributes to the diminution of crimes and enhances social mobility; (5) a factor making for more equal income distribution; (6) a source of economic growth; (7) an item carrying large externalities of various kinds; (8) a peculiar commodity bought and sold in a peculiar market; (9) an item liable to be under-invested by private individuals; and (10) an area calling for State intervention.In fact, qualitatively they said everything that is to be said about the economics of education. But they left it to their successors to tackle the quantitative aspects when more statistics and refined methods of statistical analysis become available.

Notes: In recent years a number of investigators have suggested that many economic time series exhibit significant long-run variations about an upward trend as well as short-run business fluctuations. However, several recent studies in which spectrum-analytic techniques have been employed reach negative conclusions with respect to the significance of long swings in economic activity. This paper is concerned with some of the basic problems associated with the use of spectrum estimates to test the significance of low-frequency variation in economic time series. An examination of the problem of low-frequency resolution, inadequate trend removal, low-frequency bias due to least-squares trend elimination, and the variance of low-frequency estimates leads to a qualification of some of the earlier spectrum-analytic results. This study suggests that while there is some evidence of long swings in economic activity, the problems inherent in the analysis of low-frequency variation make it extremely difficult to ascertain the statistical signifiance of these long cycles.

Notes: The behavioural interpretation which Kaldor places on his famous identity between the investment-income ratio and the profit share, and which he attempts to justify by the erroneous claim that the investment-income ratio is an independent variable in the Keynesian system, rests crucially on a model of the firm's pricing behaviour. If an alternative pattern of pricing behaviour is postulated the direction of causation is reversed with the aggregate savings propensity, and hence aggregate demand, being dependent upon the distribution of income, and subsequently to Kaldor Cartter published a model in which both savings and investment are dependent upon the distribution of income. Both models centre upon the aggregate demand—income distribution relationship, but Cartter fails to incorporate any analysis of factor share determination and he does not show how a determinate level of income is achieved, whilst Kaldor's mechanism can only function in a full employment situation.In this paper the influences of marginal productivity and Kalecki's‘degree of monopoly’ are combined with Kaldor/Cartter-type propensities relating savings and investment to the distribution of income, thereby producing a model in which the level of income and the distribution of income are interdependent and involve the determination of a position of simultaneous equilibrium. It is argued that, by retaining the influence of marginal productivity and not being reliant on a full employment situation, the model is in fact more ‘Keynesian’ than Kaldor's so-called ‘Keynesian’ model.

Notes: Baerwald, Friedrigh: Economic Progress and Problems of Labor. Scranton, Pennsylvania 1967. International Textbook Company. 353 pp.Bechtel, H. : Wirtschafts- und Sozialgeschichte Deutschlands. Wirtschaftsstile und Lebensformen von der Vorzeit bis zur Gegenwart. München 1967. Verlag Georg D. W. Callwey. 45 Karten, 8 Schaubilder, 573 S. DM 29.50Bernholz, Peter : Aussenpolitik und Internationale Wirtschqftsbeziehungen. (Frankfurter Wissenschaftliche Beiträge. Rechts- und wirt-schaftswissenschaftliche Reihe, Band 22.) Frankfurt am Main 1966. Vittorio Klostermann. 202 S.Bhagwati, Jagdish : The Theory and Practice of Commercial Policy: Departures from Unified Exchange Rates. Special Papers in International Economics, No. 8. International Finance Section, Department of Economics. Princeton 1968. 66 pp.Bihn, Willi R. : Die informationstheoretische Messung von Struktursystemen des internationalen Handels. Grundlagen und statistische Methoden. (Schriftenreihe des Instituts für international vergleichende Wirtschafts- und Sozialstatistik an der Universität Heidelberg, Bd. 5.) Freiburg 1967. Rudolf Haufe Verlag. 176 S.Bristow, J. A., and Tait, A. A. (Eds.): Economic Policy in Ireland. Dublin 1968. Institute of Public Administration. 314 pp. 55 s.Buchanan, James M. : Public Finance in Democratic Process. Fiscal Institutions and Individual Choice. Chapel Hill 1967. The University of North Carolina Press. X, 307 pp.Conolly, Violet: Beyond the Urals. London 1967. Oxford University Press. XX, 420 pp. 75 s.Dehem, Roger: Initiation à l'économique. Paris 1967. Dunod. 273 p. Fr. 25.-Eder, Rudolf: Volkswirtschaftliche Theorie des technischen Fortschritts. (Volkswirtschaftliche Schriften, Heft 111.) Berlin 1967. Verlag Duncker & Humblot. 150 S.Goffin, Robert: L'autofinancement des entreprises. Paris 1968. Editions Sirey. 186 p.Gregg, Robert W. (Ed.): International Organization in the Western Hemisphere. Syracuse 1968. Syracuse University Press. VIII, 262 pp. $6.95Jansen, Paul GÜnter : Infrastrukturinvestitionen als Mittel der Regionalpolitik. (Beiträge zur Raumplanung, herausgegeben vom Zentralinstitut für Raumplanung an der Universität Münster, Band 3.) Bielefeld 1968. C. Bertelsmann Verlag. 158 S.King, John A. : Economic Development Projects and Their Appraisal. Cases and Principles from the Experience of the World Bank. Maryland 1967. The Johns Hopkins Press. XII, 530 pp. $15.-Klement, Dieter: Strukturwandlungen des Kapitalstocks nach Anlagearten in Deutschland sett der Mitte des 19. Jahrhunderts. Tübingen 1967. J. C. B. Mohr (Paul Siebeck). XIV, 98 S.Lorenz, Detlef : Dynamische Tkeorie der internationalen Arbeitsteilung. Ein Beitrag zur Theorie der weltwirtschaftlichen Entwicklung. (Wirtschaftswissenschaftliche Abhandlungen, hrsg. von Erich Kosiol und Andreas Paulsen, Heft 25.) Berlin 1967. Duncker & Humblot. 184 S. DM 24.80McCormick, B. J., and Smith, E. Owen (Eds.): The Labour Market — Selected Readings. (Penguin Modern Economics.) Harmondsworth, Middlesex 1968. 393 pp. 9 s.Marshall, Howard D. : The Great Economists: A History of Economic Thought. New York, Toronto, London 1967. Pitman Publishing Corporation. 397 pp. $7.50Mathur, P. N., and Bharadway, R. : Economic Analysis in Input-Output Framework—with Indian Empirical Explorations. Poona 1967. 256 pp. $13.47Meinich, Per : A Monetary General Equilibrium Theory for An International Economy. Oslo 1968. Universitetsforlaget. 176 pp.Meyer, Willi : Wettbewerbsverzerrungen im internationalen Handel. Freiburg i. Br. 1967. Verlag Rombach. 299 S.Morgenstern, O., und Heiss, K. P. : General Report on the Economics of the Peaceful Uses of Underground Nuclear Explosions. Princeton, New Jersey, 1967. Mathematica. VII, 218 pp.Oettle, Karl: Verkehrspolitik. (Sammlung Poeschel, Band 54.) Stuttgart 1967. C. E. Poeschel Verlag. 100 S. DM 6.80Raiffa, Howard: Decision Analysis. Introductory Lectures on Choices under Uncertainty. Reading (Mass.)/London 1968. Addison-Wesley. XXIII, 309 pp. 43 s. Recherches récentes sur la fonction de production. Namur 1968. Centre de recherches économiques et sociales du Ceruna, Université catholique de Namur. Collection ↞Economie mathématique et économétrie↠, N0 2. 242 p.DE Roover, Raymond : The Bruges Money Market around 1400, with a statistical supplement by Hyman Sardy. (Verhandelingen van de Koninklijke Vlaamse Academie voor Wetenschappen, Letteren en Schone Kunsten van Belgie, Klasse der Letteren, Jaargang XXX, 1968, No. 63.) Brüssel 1968. Paleis der Academien. 180 pp.Saint Marc, MichÈle : Commerce extérieur de dévelopement — Le cas de la Zone franc. Préface d'André Piatier. (Collection ↞Développement économique↠ sous la direction d'André Piatier, volume XIII.) Paris 1968. Sedes. 367 p.Scheib, Hans H. : Branchenbesonderheiten. Falsche undrichtige wirtschajtspolitische Argumente. (Veröffentlichungen des Forschungsinstituts für Wirtschaftspolitik an der Universität Mainz, Band 22.) Heidelberg 1967. Quelle & Meyer. 194 S.Tarascio, Vincent J. : Pareto's Methodological Approach to Economics. Chapel Hill 1967. The University of North Carolina Press. 153pp.$6.-Turvey, Ralph: Optimal Pricing and Investment in Electricity Supply. An Essay in Applied Welfare Economics. London 1968. George Allen and Unwin. 124 pp. 30 s.Whyte, William F., and Williams, Lawrence K. : Toward an Integrated Theory of Development. New York 1968. New York State School of Industrial and Labor Relations, Cornell University, Ithaca. 89 pp. $1.50

Notes: The first to draw Soviet economists’ attention—in the early ‘sixties’—to the von Neumann model, hitherto unknown in, and indeed alien to Soviet economics, was Nemchinov. The subject was taken up by several writers: of particular interest is the impact of the construct on the model of'dynamic planning’ designed by Kantorovich and Makarov; this is the theme of the present article. MORTON and Zauberman start from a discussion of the von Neumann-type equilibrium in a long term economic plan. They then turn to several specific issues which have been for some time focal in Soviet planning thought and analyse the significance for them of the von Neumann model. These are in particular the nexus between the pace of the economy's growth and investment efficiency—traditionally recognized as central in the advance for Soviet economy; further the problems of efficiency and profit rates and in general the efficiency parameters (pricing). The authors also discuss the quest for an optimality criterion—from the angle of their theme. The article concludes with precepts for the planner as influenced by the VON Neumann ideas.

Notes: Research work is being undertaken by the Department of Orthodontics at Addenbrooke's Hospital, Cambridge, which involves studying the growth of children's faces in three dimensions. In evaluating the morphology of soft tissues, the advantages offered by photogrammetry have been recognised and this paper describes how the technique has been put into practice at the hospital where a stereometric instrument, equally suitable for use as a camera or as a projection plotter, has been constructed.

Notes: The problem of incorporating airborne auxiliary data into an aerial triangulation block adjustment is considered. The conclusion is reached that this problem can be most readily solved by the use of a fully rigorous adjustment method. The first order adjustment equations for all types of airborne auxiliary control are developed and the method of incorporating these equations into the block solution is demonstrated. The general computing problems of the aerial triangulation block adjustment are briefly discussed and a method outlined for the incorporation of tie strips, at any angle across the block, into the adjustment without unduly increasing the storage requirements for the solution. The problem of correctly weighting the different types of available data is discussed. The paper concludes with a demonstration of the improved accuracy possible if precise aerial triangulation data are combined with apparently crude absolute airborne data.

Notes: The International Society for Photogrammetry held the Xlth International Congress at Lausanne during July 1968. The authors review the activities of five of the seven I.S.P. Commissions.

Notes: In August 1966 aerial photography, using five film/filter combinations, was obtained of the Dyfi Estuary, on the coast of Cardigan Bay. The paper discusses some of the problems associated with a project involving several emulsions and in which photography of the inter tidal area must be achieved as near low water as possible. Preliminary results confirm that, in general, colour and false colour photographs improve both the speed and reliability of interpretation when compared to monochrome photographs.

Notes: Book reviews in this article:APPLIED OPTICS: A GUIDE TO MODERN OPTICAL SYSTEM DESIGN. Vol. I. By L. Levi.MANUAL OF COLOR AERIAL PHOTOGRAPHY. Editor J. T. Smith.

Notes: This paper describes the planning and implementation of a very extensive aerial survey contract undertaken by Hunting Surveys on behalf of the Hong Kong Government. From photography carried out during January and February 1963, photogrammetric plotting at 1 : 600 and 1 : 1200 proceeded steadily over a period of 5 years to the point where all but the highest land in the Colony had been surveyed at one or other of these two large scales.The problems arising from the rather unique terrain conditions and the urban and industrial development of Hong Kong are dealt with mainly from the photographic and photogrammetric aspect but reference is made to the contribution of the Crown Lands and Survey Office of the Public Works Department of Hong Kong, who provided all ground control and undertook field verification.

Notes: In order to be able to predict the accuracy which may be expected from an aerial triangulation adjustment, it is required that the observed quantities (parallaxes and co-ordinates) should be introduced with their proper weight and correlation coefficients. After a review of the present knowledge of these coefficients for the usual photogrammetric observations, the conclusion is reached that this knowledge is inadequate for the purpose. Further research in this field is recommended.