ZOOLOGY FOR MEDICAL STUDENTS 



CHAP. 



If we follow out the fate of the microspheric individual (Fig, 8, 7) we 

 find that it reproduces by a process of multiple fission or schizogony 



P 



chr 



FIG. 8. 



Life -hi-torv <>f I'olystomella according to Lister, i, Megalospheric individual ; za and 26, gametes 

 derived from two different megalospheric individuals ; 3 and 4, syngamy ; 5, zygote (central proto- 

 plasm of new mirrospheric individual) ; 6, early stage in growth of microspheric individual ; 7, micro- 

 individual ; 8 and 9, young megalospheric individuals derived from 7. b, Protoplasmic 

 bridge; chr, rhniinidia ; M, central protoplasm of megalospheric individual; m, central protoplasm 

 of microspheric individual ; n, nucleus ; p, peg-like projections of cytoplasm. 



