ALBERT

Notes: SYNOPSIS. Silver impregnation techniques were used to study the silverline system of three species in the genus Spirostomum. It was concluded that for those species studied in the general area of Washington, D.C., the average numbers of ciliary meridians in S. teres, S. minus and S. ambiguum are 18, 24 and 46 respectively. Seventy-six % of the measurements in S. teres and S. ambiguum and 84% of the measurements in S. minus deviate from the mean by less than 1 standard deviation.

Notes: SYNOPSIS. Blepharisma seculum sp. nov. is described as a small-sized blepharisma with a compact, spheroid macronucleus and a distinct curvature of the body anteriorly. A comparison of this form with other species of the genus Blepharisma subgenus (Compactum) is given.

Notes: SYNOPSIS. Lymphotropha tribolii gen. nov., sp. nov. (Neogregarinida, Schizocystidae) is described from the haemocoele of Tribolium castaneum (Herbst) (Coleoptera, Tenebrionidae). The trophozoites are large, ovoid and uninucleate with distinct longitudinal striae. Schizogony occurs in one type of cycle only, each schizont giving rise to up to 8 merozoites. Gametocytes are uninucleate when they associate. Up to 16 oocysts each with 8 sporozoites are formed in each gametocyst. The oocysts are lemon-shaped, and sporozoites emerge from the poles.The parasite causes considerable mortality in young larvae, though its pathogenicity is probably inferior to that of Farinocystis tribolii Weiser.

Notes: SYNOPSIS. Sarcocystis garnhami n. sp. is described from an opossum, Didelphis marsupialis. Its distinguishing characters are the spiny cyst wall, 6–8 μ thick, and the size of the spores, 5.3–6.9 μ in length and 1.3–1.9 μ in breadth. Sarcocystis darlingi, Brumpt 1913 is considered Besnoitia darlingi (Brumpt, 1913) n. comb.

Notes: SYNOPSIS. An epizoic suctorian from Gulf of Maine coastal waters, designated as Paracineta sp., is described. Morphological measurements are given for 23 small, medium, and large specimens. Mean length was 200 μ and average cell body diameter 39 μ. Of 21 copepod species and 19 zooplankton groups examined, only copepods of the genus Metridia showed any Paracineta attached. Suctorian occurrence was, with a single exception, limited to adult copepods, with the larger females showing the heaviest incidence. Differences in areal occurrence were observed with greatest incidence of Paracineta on M. lucens in the eastern and central Gulf, and lowest numbers in the western area. This differential occurrence is accredited to an apparent cold water affinity of the suctorian. It is suggested that Paracineta could be carried into the Gulf during periodic intrusions of cool Nova Scotian water, reaching the western area in the southwesterly flowing Gulf of Maine eddy system. No significant differences in vertical distribution were found in Paracineta incidence on Metridia among the depths sampled (0, 10, 30, and 60 m). No harmful effect of Paracineta on Metridia was evident.

Notes: SYNOPSIS. The intralymphocytic stages of Theileria parva, T. lawrencei and T. annulata have been cultivated for several months in tissue cultures of bovine lymphocytes associated with baby hamster kidney cells. In established cultures the theilerial particles multiplied at about the same rate as the host cells, the percentage of infected cells and the mean number of parasite particles per cell remaining nearly constant.During mitotic division of the host cell the theilerial body becomes closely associated with the spindle fibres and is pulled apart and distributed to both daughter cells in late anaphase. The single theilerial particles (chromatin) within the theilerial body divide by binary fission; their division is not synchronous with that of the host cell.

Notes: SYNOPSIS. A sulfolipid, isolated from the phytoflagellate, Ochromonas danica, and from its medium, constitutes over 50% of the sulfur of the cells. It is bound to protein and excreted by the phytoflagellate. When the S35-labeled sulfolipid was placed in the medium it was incorporated by the cells without cleavage of the sulfate group. Thus it passes back and forth between the growth medium and the cells.The sulfolipid has been found in O. danica, O. malhamensis, Tetrahymena pyriformis, Chlamydomonas sp., Pseudomonas sp. (sea water bacterium). It was identified in the culture medium of O. danica, O. malhamensis, Chlorella pyrenoidosa, and Streptomyces griseus. Preliminary evidence was obtained for its presence in the growth medium of white clover and sorghum.

Notes: SYNOPSIS. The normal cycle of asexual reproduction in Euplotes eurystomus was subjected to a detailed morphological study using whole-mounted and sectioned material prepared by the method of silver impregnation. The cycle was arbitrarily divided into 7 stages (numbered 0–6) characterized by nuclear and cortical events. Particular attention was focused on the development of the oral primordium (OP), and the production of new kinetal cilia (or “dorsal bristles”).The OP is interpreted as originating from an invagination or infolding of the parental cortex, followed by considerable in situ growth and differentiation beneath the cell surface. It is suggested that differentiation beneath the parental cell surface may in some way facilitate morphogenesis of other cortical structures without necessitating dedifferentiation of the parent's buccal apparatus. During stage 6, the division constriction plays an important morphogenetic role in shaping the opisthe's buccal apparatus.During stage 4, a zone of ciliary increase (ZCI) appears in the central portion of each kinety. New kinetal cilia arise as semi-circular clusters of 1 to 9 kinetosomes flanking each old basal structure; the latter persist until the new organelles are well established. An analysis of total kinetal cilia in animals during stages 0 to 3 indicates that, while ciliary number varies according to animal size, there is no increase in cilia prior to formation of the ZCI.Several aspects of the asexual cycle in Euplotes seem to bear importantly on the more general problem of ciliate morphogenesis. The pattern or gradient concept might be useful in the analysis of factors determining primordial sites, although later development of the primordium into a specific organelle or organelle system is probably controlled by autonomous epigenetic processes that are somewhat independent of the parental cortical pattern. The hypothesis of kinetosome continuity cannot account for the origin of primordial fields in cortical regions remote from pre-existing kinetosomes, as observed in Euplotes. The initiation of morphogenetic activity on the cortex is closely correlated with, and may be causally related to, the appearance of replication bands in the macronucleus. The known metabolic significance of these bands, particularly the release of nuclear RNA, lends support to this suggestion.

Notes: SYNOPSIS. Experiments were performed to ascertain the effect of heat and cold on oral and micronuclear development in synchronized Tetrahymena pyriformis WH-6. The developing oral primordium becomes insensitive to cold sometime during stage 2. Cold shocks cause the reversion of many stage 2 primordia to stage 1. Cells so affected are set back in division. The delayed division is always asynchronous. When heat shocks are applied prior to late stage 4, the developing primordium will regress. High temperature shocks applied at later stages permit continued development. However, when the cell begins to cleave at the high temperature, division is frequently arrested and the new oral areas regress. Subsequent cell separation is greatly delayed and asynchronous.Heat and cold affect the micronucleus in the same way. Both agents prolong the arrest of mitosis brought about by the synchronizing treatment. A temperature shock is ineffective if applied after there is a space completely separating the chromosome groups, so that mitosis is completed in the presence of the agent. Bimicronucleate chains result in those cases in which division is arrested by heat shocks.It is suggested that the different phases of sensitivity to heat and cold may reflect different types of syntheses necessary for development of the oral primordium. Division arrest and subsequent oral replacement might possibly be related to high temperature induced changes in the physical state of the ciliate cortex.