and Reproductive Phenomena of the Amoeban Rhizopods. 453 



the process was followed by any modification in the appearance 

 of the sarcode-substance generally or the nucleus, specimens in 

 which fusion had taken place, and which, owing to their very 

 large size and hyaline nature, were admirably adapted for ex- 

 hibiting any change, were kept carefully isolated in shallow glass 

 cells for several days. In these examples, however, there was 

 no other change observable than the increase in bulk, which 

 dated, of course, from the time that fusion was complete. 



Those who have watched the behaviour of Actinophrys when 

 in search of food, are aware with what stolid but unfailing 

 energy it frequently drags into its interior organisms not only 

 superior to it in type, but in activity of movement. Yet, withal, 

 it succumbs to Amoeba. It is possible that the more rapid loco- 

 motive power oi Amoeba may serve in some degree to give it the 

 mastery ; but, on the other hand, there is evidently some other 

 obstacle to an Amoeba becoming a prey to Actinophrys, inasmuch 

 as the largest specimens of the latter generally decline all contest 

 with Amoeb<B, even when sufficiently small to ensure their de- 

 struction were it a mere question of strength. When, by accident, 

 the two organisms come into collision, the Amoeba seems to be 

 forthwith aroused to an unwonted degree of activity, and an 

 effort is made by it to envelope the Actinophrys with the folds of 

 its pseudopodia. Failing, however, in the attempt to secure the 

 entire mass, the Amoeba now employs its pseudopodia in tearing 

 out portions of its adversary ; and these are in due course con- 

 signed to vacuolar cavities. On one occasion I saw nearly half 

 of a large Actinophrys transferred piecemeal, after this fashion, 

 into the interior of its captor — the several fragments torn out 

 (not simultaneously, but by a series of consecutive efforts) be- 

 coming rapidly absorbed under the digestive action to which they 

 were immediately subjected (see PI. VIII. fig. 18). In so far, 

 therefore, as it is legitimate to draw conclusions from appearances 

 and the behaviour of the organisms in question, instead of con- 

 firming the opinion as to their betokening a reproductive act, 

 they tend rather to show that, between the so-called zygosis of 

 two specimens of Actinophrys and the inception of an Actino- 

 phrys by an Amoeba, there is but this difference — that in the one 

 case the act is akin to cannibalism, whereas in the other it is 

 not so. 



In tracing the development of the young Amoeba, either from 

 the free sarcoblasts or large mulberry-shaped masses that re- 

 semble acapsular nuclei, the different steps are essentially 

 similar. They would seem, in the first place, to be associated 

 with an increase of the more fluid hyaline protoplasm within 

 which the granules of these bodies are suspended, and which may 

 increase to any extent without any alteration taking place in its 



