ENDOGENOUS DIVISION OF GRANULES 



379 



elongates (2-4 nuclei abreast), and each of its 64 cells in turn, following 

 on the disappearance of the microsomes, acquires four equal, refrac- 

 tive, spherical granules (4 microns in diameter), and the tissues thus 

 take on a granulated appearance, the nuclei and cell-walls being 

 almost completely hidden by the closely packed granules. By the 

 time the cephalad part of each tissue enters the duct the caudad part 

 has undergone a further change, in that the four granules, each dividing 

 endogenously into four similar but smaller spherical granules, popu- 

 late each cell with 16 granules (grn 4 and grn 16, Fig. 2). 



This very interesting behavior of the granules (Figs. 7 and 9) 

 more than suggests a different order of mechanism from that typical 



Fig. 11 



:1200' 



Fig. 8. Reduction division. Sublimate-acid carmine toto preparation. The 

 smallest chromosome differed somewhat in size in the two sets. Fixation less delicate 

 than with acid methyl green. 



Fig. 9. Two granules from the spermatidia of S. parasitifera;one showing 4 

 smaller granules formed endogenously, the other 8. The right hand granule is from 

 near grn 4, Fig. 2. The left hand granule, taken from farther back in the testis, where 

 microscopic details are so fine that exact relationship of granules and their descendants 

 has not as yet been fully deciphered. 



Fig. 10. Spermatidia each containing sixteen refractive spherical granules. From 

 life. The cell walls and nuclei of this tissue are nearly invisible in life. 



Fig. 11. Nuclear spindles in later mitoses of spermatidia taking place in vas 

 deferens. Polar views of spindles show 7 chromosomes; see small figures to right, 

 from another part of the same specimen. 



of cell division, but since irritability, ingestion, transportation, trans- 

 formation and so forth, all seem involved, it appears necessary to 

 base the concept on what is known of cell physiology and mechanics; 

 the changes, however, are carried out on a smaller scale and doubt- 

 less with a more limited variety of molecules forming a different 

 kind of plasm litoplasm. In short, the facts indicate a distinctly 

 lower order of "organism." Many of what now are often called 

 lower organisms might better be regarded simply as less multiplicate. 

 Thus certain ciliates are smaller and less multiplicate, rather than 

 "lower," as compared with nemas for instance. This matter is 



