360 The Mickoscope. 



however, before another amoeba chanced to touch the heliazoan, and 

 this time with better success to the heliazoan. The amoeba, as soon 

 as it touched the heliazoan, spread out a little on it, and at the same 

 time the protoplasm of the heliazoan began to flow around and to 

 enclose the amoeba, which now made several efforts to escape, but in 

 vain, for within a few minutes a fine film of protoplasm had 

 surrounded it, and the amoeba was within the heliazoan, (Fig. 19). 

 A quantity of water was also enclosed with the amoeba, and in this 

 it exhibited considerable activity, even after it had been carried 

 nearly to the center of the heliazoan, (Fig. 21.) It was not long, 

 however, before the amoeba had assumed a globular form and 

 become motionless. I mentioned this instance in which the heliazoa 

 eat other animals merely to bring out the striking difference between 

 the process and that observed when they eat their own species. 



Dr. Joseph Leidy* speaks of having found several globules of 

 granular protoplasm, with vascuoles and rays, and alludes to their 

 probable connection with this species of heliazoa. I have repro- 

 duced in Fig. 24 one of his figures of these bodies, and think that 

 there is every reason to believe that they are what he suspected them 

 to be. 



Reproduction. — It is not uncommon to find heliazoa in the 

 process of reproduction by fission. In fact, if heliazoa be kept for 

 any considerable length of time, they are almost certain to be found 

 in the act of reproducing by this means. I have observed them 

 divide by keeping them in a watch-glass under the microscope, and 

 in one instance I watched uninterruptedly the process from an oval 

 heliazoan before the constriction began to appear, up to the division 

 and entire separation into two animals. A complete set of di*awings 

 was made to illustrate the different steps, and I find, by referring to 

 my notes, that one of the drawings is almost identical with Fig. 10, 

 which represents the heliazoa in the process of union. 



As regards reproduction in the heliazoa outside of the well 

 known process of fission, all 1 can say is from a philosophical stand- 

 point, as no direct observations have been made outside that of the 

 finding of the young. But the presence of young has got to be 

 explained in some way. From Dr. Leidy " Fresh-water Rhizopods," 

 p. 2(30, I find that "according to Stein, Carter, and other authorities, 

 A. Eichhornii contains many nuclei, large individuals having a hun- 

 dred or more." Whether this has any connection with the heliazoan 

 having devoured individuals of its own species and thus to have 



* " Fresh-water Rhizopods of North America," p. 2G2-3. 



