CYTOPLASMIC INCLUSIONS 169 



rowsky (1931-33) on OpaUna ranarum; MacLennan (1936, 1937) on 

 Ichthyophthirius multiflns; and Joyet-Lavergne (1926 on) on several 

 Sporozoa, supplemented by the observations and experiments of Daniels 

 (1938) on similar species. Since a summary of the individual granules 

 has been given in the previous sections, only a general account of each 

 granule will be given in this comparison. 



The number of types of granules ranges from two in the marine 

 amoeba Flabellula to at least six in Ichthyophthirius and some of the 

 Sporozoa. In Flabellula there are only digestive granules and small gran- 

 ules of unknown composition and function. This small number contrasts 

 sharply with A. proteus, which has four types of granules of cytoplasmic 

 origin: refractive bodies ( dictyosomes ) , alpha granules unknown in 

 composition and function, mitochondria (beta granules), and neutral 

 fat granules. In addition to these granules there are two types of crystals, 

 blebs on these crystals, and vacuole refractive bodies, all of which arise 

 in connection with the food vacuole. The two ciliates Opalina and Ich- 

 thyophthirius also show marked differences in number of granules — the 

 former with only four types and the latter with seven. Opalina has segre- 

 gation bodies, endosomes (mitochondria?), intermediate lipoid bodies 

 (endoplasmic Golgi), and neutral fat, while Ichthyophthirius has inter- 

 mediate lipoid bodies (endoplasmic Golgi), neutral fat, excretory gran- 

 ules (ectoplasmic Golgi), mitochondria, paraglycogen, and protein 

 bodies. Gregarines and Coccidia have at least one type of Golgi body, 

 neutral fat, one or two types of mitochondria, paraglycogen, one or two 

 types of protein reserves, and neutral red bodies, a total of six to eight 

 types of granules, allowing for differences in the accounts of Daniels and 

 Joyet-Lavergne. Not all the Sporozoa present such a complicated picture, 

 since there are probably not more than three types of granules in Plasmo- 

 dium: mitochondria, segregation granules, and pigment. These marked 

 differences, which appear even with a crude comparison based only on 

 number of types of granules, show clearly that at best only very few gran- 

 ules could be universal. Furthermore, the number of granules varies in- 

 dependently of the relationships of the Protozoa involved, since both large 

 and small numbers of granules are found in Protozoa of the same class. 

 The immediate facts which stand out with respect to the staining re- 

 actions of these five species of Protozoa are that in each species are 

 granules or vacuoles which are stained specifically by Janus green B 



