The Microscope. 359 



I have observed a number of large heliazoa capture the young- 

 est individuals, and in all cases, as soon as the young animal 

 touched the ray of the larger, it appeared, so to speak, to form a 

 part of it, and would sometimes assume an oval form and remain on 

 the ray, looking exactly like the little knobs of protoplasm which 

 are frequently seen there, except that it would be larger; and then, 

 again, I have seen them flow down the center of the ray, while the 

 ray itself suffered no appreciable change. In one instance, however, 

 which came under my observation, a moderately sized heliazoan 

 (Fig. 17) captured by the tip of its ray one of the youngest indi- 

 viduals (Fig. ]6), and while watching to see what would happen to 

 this young one, the ray of a large heliazoan (Fig. 18) came in 

 contact with the larger of the former animals. Out of curiosity 

 merely, I watched to see the result of this extraordinary union, and 

 found that the largest heliazoan drew its captured brother to itself 

 and united with it before the smallest individual had touched the 

 body of the one to which it was attached . The smallest heliazoan 

 then appeared to be fastened to a ray of the largest animal, which, 

 however, soon drew it to itself and the two united. 



Quite a different process from the one we have been discussing 

 occurs when the heliazoan encounters food consisting of other 

 animals or plants. I have no doubt but that the youngest heliazoan, 

 as well as those of all stages, are able, and generally do, develop 

 and reach maturity by the use of no food other than that of other 

 animals and plants ; but there is also no doubt that this is a process 

 requiring considerable time as compared with that which occurs 

 when they chance to meet with their own kind, since in the former 

 case the food has to be digested, while in the latter it has not. It 

 was my good fortune to find a large heliazoan which had just 

 captured an infusorium and partly surrounded it. In a few minutes 

 the infusorium was completely enclosed, a clear space remaining 

 around it, however, and gradually it was moved near the center of 

 the animal, where it could be seen slowly moving its cilia in 

 the little water which immediately surrounded it, and which 

 separated it from the protoplasm of the heliazoan. (Fig. 19, 21.) 

 Presently an amoeba came in contact with the heliazoan and 

 appeared to stick to it more or less, and to constantly try to move 

 away from it. The heliazoan made several efforts to surround it, 

 bu^t the amoeba in every case moved out before fairly imbedded, and 

 finally, after several minutes of hard struggling to ascertain which 

 was to be victorious, the amoeba escaped. It was but a short time, 



