CANNIBALISM IN AMOEBA 695 



the same rock as did the parasite hypothesis. It fails to 

 explain the occurrence of several amoebae enclosing one 

 another, as are shown in PL 28, tigs. 1 and 2. This could, it is 

 true, be interi)reted as endogenous budding with pathological 

 delay of the birth of each bud, so that an appearance of con- 

 centric fission rt^sulted ; but there seems to be no necessity for 

 so fantastic a view, when the structure can be explained 

 naturally and simply as the result of cannibalism. 



Lastly, it is difficult to understand why endogenous budding, 

 if it occurs in the Amoebaea, has not been fully described 

 already, seeing that such a vast amount of work has been done 

 on these organisms. It is true that Penard (21) has made 

 several references to the occurrence of so-called ' embryos ' in 

 Pelomyxa and in various amoebae. With regard to Pelomyxa, 

 he says that ' in the month of October, 1900, the greater part 

 of the individuals examined contained, in their bodies, true 

 embryos. These embryos, apparently swimming in the 

 plasma, . . . showed as little grey masses, spherical, ovoid or 

 pyriform, in the interior of which one saw some little, brilliant 

 grains, one or two vacuoles and a vague appearance of nuclei. 

 Isolated by compression of the Pelomyxa the embryos pushed 

 out slowly prolongations in the form of little waves or lobes 

 and continually deformed themselves in their entirety.' He 

 was also able to convince himself of the presence of a contractile 

 vacuole, which ' only functioned in a lazy manner ', and he 

 was sure of the presence of a ' nucleus, round, with a nuclear 

 membrane already formed and distinct, with nuclear sap and 

 a central nucleolus and one or two other spherules, . . . which 

 seemed to represent nuclei also '. He adds his opinion that 

 ' the presence of these embryos, living in good health in the 

 plasma of the Pelomyxa and usually multinucleate, seems to me 

 to indicate that they are products of the animal itself and not 

 parasites '. 



This description suggests that he may have been dealing with 

 either parasites or with amoebae of the Amoeba limax 

 type which had been ingested by the Pelomyxa ; but doubt is 

 thrown over the whole of the observations ])v his statement, 



