CANNIBALISM IN AMOEBA 689 



Biitschii (2), with Lecytliium hyalinum, which also may 

 become parasitic upon Amoeba proteus, Rotifera, 

 Crustacea, &c., during its sexual cycle. Buck states that this 

 organism may, when it is parasitic in Amoeba and other 

 organisms, closely resemble Sphaerophrya. But I am con- 

 vinced, after reading his paper and studying his figures, that 

 Phonergates has no points of resemblance to the spheres 

 here described, except, perhaps, that it is about the same size. 

 Penard {21 d) has described in an amoeba which he names 

 Amoeba alba, a parasite similar to one seen by Buck in 

 Arcella and later found by Dangeard (7 c) in the Heliozoa 

 Nuclearia simplex and Heterophrys dispersa and 

 called by him Sphaerita endogena. The form seen by 

 Penard belongs to the Chytridiaceae, and he thinks that it is 

 similar to that described by Chatton and Brodsky (5) in 

 Amoeba limax. The latter authors discuss the whole 

 question of these and allied parasites, and it is obvious that 

 none of these parasites resembles the spheres described above. 

 Another parasite, Nucleophaga amoeboea, allied to 

 the above, has also been described by Dangeard (7&), Penard 

 {21 d), and others. It attacks the nucleus of various amoebae. 

 Doflein (9) has further described the formation of giant nuclei 

 in Amoeba vespertilio, which is the amoeba with which 

 we are dealing, due to a parasite which he regards as being 

 closely allied to, if not identical with, the Nucleophaga of 

 Dangeard. The spheres described above have, however, 

 obviously nothing to do with this or any other nuclear parasites, 

 since the nucleus of the amoeba containing the sphere was 

 always intact and normal and the sphere itself had a nucleus 

 of its own, which was very similar to that of the amoeba 

 which contained it. 



Leidy (18) has described and figured a number of interesting 

 inclusions in Amoeba proteus and other species. His 

 observations were, however, made upon the living object only, 

 and it is unfortunately impossible to determine from his figures 

 and descriptions what was the real nature of these inclusions. 

 Some of his figures of them, described by him as nuclei, might 



