ELISHA MITCHELL SCIENTIFIC SOCIETY. 93 



ing difference between the process and that observed when 

 they eat their own species. 



Dr. Joseph Leidy* speaks of having found several glob- 

 ules of granular protoplasm with vacuoles and rays, and 

 alludes to their probable connection with this species of 

 heliazoa. I have reproduced in figure 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 oral heliazoan before 

 the constriction began to appear, up to the division and 

 entire separation into two animals. A complete set of 

 drawings was made to illustrate the different steps, and I 

 find by referring to my notes that one of the drawings is 

 almost identical with figure 10, which represents the helia- 

 zoan in the process of union. 



As regards reproduction in the heliazoa outside of the 

 well-known process of fission, all I can say is from a philo- 

 sophical 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's "Fresh-water Rhizopods," p. 260, I find 

 that "according to Stein, Carter and other authorities, A. 

 Eichhornii contains many nuclei, large individuals having 

 a hundred or more." Whether this has any connection 

 with the heliazoan's having devoured individuals of its 

 own species and thus to have retained their nuclei, and so, 

 by continually adding to the number every time it captured 



Fresh-water Rhizopods of North America," page 262-3. 



