No. I.] SPERMATOGENESIS OF BATRACHOSEPS. 13 



retain in this paper have the advantage of distinguishing between 

 the two spheres, and have besides the priority. Upon the 

 value of the latter I shall, however, not insist, and I am willing 

 at any time to discard any words introduced by me or by any 

 one else as soon as better ones are found, but not until then. 



Position of the Spheres. 



As will be seen from a perusal of Figs. 10-17, the spheres 

 are only situated on the cell axis when they are in a stage 

 of comparative rest, and at a time when the spheres and 

 the nucleus appear to balance each other. If, on the other 

 hand, we examine such figures as 42 and 45, we find that the 

 spheres, especially the granosphere, have a different position 

 relative to the central spindle and the nucleus. Instead of 

 being situated on a line passing through both the central spin- 

 dle and the nucleus, we find them situated on a line passing 

 through the equator of the central spindle. From this we can 

 formulate a rule that the position of the granosphere during 

 the radiosomic process is dependent upon the position of the 

 central spindle ; and vice versa, that the position of the central 

 spindle is dependent upon that of the granosphere. Whatever 

 be the relative position of the nucleus on one side, and the 

 granosphere and the central spindle on the other side, the cen- 

 tral spindle will always be so situated that a line passing 

 through its equator will also pass through the granosphere. 

 The object of this relative position of spheres and central 

 spindle is undoubtedly to enable the two opposite poles of 

 the central spindle to draw an equal amount of nourishment 

 or material from the granosphere. 



As regards the mutual position of the two spheres, I expect 

 to show that they are not directly dependent on each other, 

 and that the position of the granosphere inside of the plasmo- 

 sphere is probably regulated by convenience more than by 

 dependence. If the granosphere were situated anywhere else 

 it would not be able to furnish the central spindle with the 

 material required for its development. The plasmosphere 

 again, which furnishes material for the mantle fibers and for 

 the new cell wall, must of a necessity be on the outside, in 



