CANNIBALISM IN AMOEBA 697 



Much more plausible, however, are the accounts of endo- 

 genous budding in amoebae given by Liston and Martin (19), 

 Wherry (30), and Hogue (15). The last-named worker also 

 describes the formation of ' exogenous ' buds, by the streaming 

 out of chromatin granules from the karyosome into the ecto- 

 plasm, where they collect to form the nuclei of the exogenous 

 buds. Her figures and description, however, suggest that the 

 so-called chromatin granules were either artefacts or parasites 

 like the Chytridiaceae referred to above. 



Hogue's figures of the endogenous buds, like those of Wherry, 

 are much more convincing and show a striking resemblance to 

 the figures illustrating this paper. Neither of these workers, 

 however, has given a detailed description of the so-called 

 ' buds ', nor was the development of the ' buds ' followed. 

 Had this been done in all probability a different conclusion as 

 to their real nature would have been reached. It should be 

 noted, also, that in both these cases the amoebae were studied 

 in agar media, which cannot be regarded as a sound method 

 of cultivating these organisms. Further, the cultures were 

 crowded with amoebae, a state of affairs which would tend to 

 encourage the ingestion of the amoebae by one another. 



Liston and Martin (19) have described endogenous budding 

 in a large amoeba from liver-abscess pus. This amoeba also 

 was studied on agar media. Liston says that he saw an amoeba 

 develop three or four ' buds ' within its body while under 

 observation and that these were liberated. Older and larger 

 amoebae might contain as many as six ' buds ' in various stages 

 of development. If this were so, it is unlikely that they were 

 true endogenous buds at all, because endogenous buds are 

 usually formed of a certain definite size which does not increase 

 or change before they are born. Liston also states that the 

 ' buds ' became recognizable in the amoebae ' when a larger 

 mass of chromatic material was assembled than could be 

 reasonably explained on the supposition that it was formed from 

 ingested bacteria ', that the ' buds ' were formed around these 

 masses of chromatic material, and that these masses then 

 became the nuclei of the ' buds '. Martin, in a study of the 



