1036 PARASITES OF PROTOZOA 



being pointed. According to Hafkine, multiplication of Holospora takes 

 place in two ways. During development, for a time there is a rapid 

 transverse division. The spiral form of H. iindulata develops after di- 

 vision ceases; the other two species remain straight. The dimensions in- 

 crease in this phase, which was supposed by Hafkine to represent a 

 transformation into resistant spores. H. undiilata in this phase loses its 

 pale, transparent aspect, and becomes more refractive at one of its 

 extremities. This modification extends until the whole organism is re- 

 fractive; sometimes it is divided into three or four parts of diiferent 

 refractivity. Of the other reproductive process, there are only traces in 

 H. undulata; but it is more frequent in the other two species. A bud 

 forms at one of the extremities, and grows into a cell like that from 

 which it originated. This type of reproduction, according to Hafkine, 

 makes Holospora transitional between yeasts and Schizomycetes. He 

 maintained, as did Metschnikoff and Fiveiskaja, that there are grounds 

 for not placing the parasite among the typical bacteria. Fiveiskaja studied 

 only H. obtusa in the macronucleus, and did not find any parasitized 

 micronuclei. She found the parasites to be elongated, straight, or slightly 

 curved rods from 12 to 30 \\ in length by 0.6 to 0.8 \x in width, often 

 showing difi^erential refractivity or stainability. Part, up to half, or all, 

 of a rod might be dark and the other part or other entire rods clear — 

 a characteristic that appears in many of the early drawings (Biitschli, 

 1876; Balbiani, 1893). 



Petschenko (1911), who studied an organism considered to be a 

 cytoplasmic parasite, named it Drepanospira miilleri and assigned it to 

 the Spirillaceae. He remarked that the external aspect of this organism 

 is the same as that of Holospora undulata and H. elegans. The parasites 

 develop from a group of curved rods in the cytoplasm to a large ellipsoi- 

 dal mass, almost filling the body. In the vegetative period, the micro- 

 organism is a spiral with a nuclear portion near the anterior end, and it 

 shows helicoidal movement. The karyoplasm separates into granules and 

 bands, and endospores are said to be developed. There is a resting period 

 in which the rod is small, curved only once, and the nuclear substance 

 occupies from half to almost all of the cell. There is said to be no 

 cell division, reproduction being only by the endospores. Petschenko 

 stated that the essential difference from Holospora lies in the fact that 

 Hafkine did not establish in his parasites the presence of nuclear ele- 



