Page:Bergey's manual of determinative bacteriology.djvu/949

 and have been placed in the special genus Holospora Haffkine. The spores appear to resemble the endospores found in the genus Bacillus Cohn. Because the majority of these intracellular parasites are so highly specialized that they, like rickettsias and viruses, cannot be cultured outside of the cells that they parasitize, the descriptions that have been published of these parasities were arranged in an appendix to the order RickeUsiales in the sixth edition of the Manual (1948, p. 1121). However, these protozoan parasites have been described by those who have studied them as being related to quite a variety of genera of bacteria belonging in various orders of the class Schizomyceies. Furthermore, these organisms are not in any sense of the word intermediate in character between rickettsias and viruses, even though all are highly specialized intracellular para- sites. For these reasons the parasites of protozoa are placed in this edition of the Manual in an Addendum to Class II, Schizomyceies. While onl}^ about one dozen species of these bacteria have as yet been described and named, several additional species have been well described without having been named. Still other species are known to exist. No special student of the group has as j^et attempted to place these interesting organisms in relation to recognized families and genera of bacteria more definitely than is indicated above. The organisms in question are, as yet, best known to protozoologists and are rarely mentioned in textbooks of bacteriology. Their existence suggests that other groups of invertebrate animals may suffer from similar bacterial dis- eases as yet unknown. — The Editors. GENERA AND SPECIES OF PARASITES OF PROTOZOA.* I. Species placed in special genera: Genus A. Caryococcus Dangeard, 1902. (Compt. rend. Acad. Sci., Paris, 18^, 1902, 1365.) Ca.ry.o.coc'cus. Gr. noun caryum nut, kernel, nucleus; Gr. noun coccus berry, coccus; M.L. mas.n. Caryococcus nuclear coccus. Spherical organisms parasitic in the nucleus of Euglena. The type species is Caryococcus hypertrophicus Dangeard. 1. Caryococcus hypertrophicus Dan- 2. Caryococcus cretus Kirb}% 1944. geard, 1902. (Compt. rend. Acad. Sci., Paris, (Univ. CaHf. Publ. Zool., 49, 1944, 240.) i34, 1902, 1365.) cre'tus. L. p. adj. cretus visible, dis- hy, per. tro 'phi. cus. Gr. pref. hyper over, cernible. more than; Gr. adj. trophicus nursing; Spherules 1.0 to 1.5 microns or more in M.L. adj. hypertrophicus overfed, causing diameter. Appear clear in preparations with hypertrophy. usually a chromatic, sharply defined, cres- Occurs in the nucleus as an agglomera- centic structure peripherally or interiorly tion of close-set, spherical corpuscles. The situated, sometimes with two such bodies nucleus increases considerably in volume, or several chromatic granules. Parasitic in the chromatin is reduced to thin layers nucleus. The parasitized nucleus is enlarged against the membrane, and the interior of only moderately or not at all, and the chro- the nucleus is divided into irregular com- matin is altered but not greatly diminished partments by chromatic trabeculae. in amount. Parasitic in the nucleus of a flagellate Parasitic in the nucleus of a flagellate {Euglena deses). {Trichonympha corbula) from the intestine October, 1946; revised by Prof. Bronislaw M. Honigberg, University of Massachusetts, Amherst, Massachusetts, March, 1955.
 * Prepared by Prof. Harold Kirby, Jr., University of California, Berkeley, California,