No. I.] SPERMATOGENESIS OF BATRACHOSEPS. >] ^ 



the opportunity for a stage of growth, enabling it to 

 increase to about twice its former size. In this stage the 

 daughter-cells become entirely separated, after which they are 

 to be termed "spermatocytes." If we consider the spermato- 

 cyte to begin with the reappearance of the chromosomes, then 

 this chrysanthemum stage should be counted as belonging to 

 the spermatocyte and not to the auxocyte. If we date the 

 appearance of the auxocyte from the stage of growth, then we 

 ought also to date the appearance of the spermatocyte from 

 the stage of growth of the nucleus. 



C. The Chromosoviic Process in the Spermatocytes. 



The Chrysanthemum Stage, in which the chromosomes have 

 the form of staples and horseshoes. This stage is similar to 

 the one described as the last one of the previous cell genera- 

 tion (Figs. 62-70). Numerous fiber cones. 



Checkerboard Stage. — The staple-shaped chromosomes of 

 the previous stage have grown and become elongated, and the 

 chromomeres have become so separated as to be spread over 

 the nucleus almost as the squares on a checkerboard (Figs. 

 71-82). In the first half of this stage the fiber cones are dis- 

 appearing, either completely or with the exception of two, 

 which later join to form the new central spindle. The spheres 

 are being reconstituted during this stage. 



Contraction Stage. — The scattered chromomeres again ap- 

 proach each other and form strongly beaded chromosomes. 

 The nuclear membrane is being dissolved by the fiber cones or 

 by the fibers of the new central spindle (Figs. 83-86). 



Angular Chro7noso7nes. — In this stage the chromosomes 

 straighten out and become narrower, cross each other at vari- 

 ous angles, and the chromomeres become so fused that they 

 can hardly be distinguished one from the other (Fig. 2,'j). 



Knotted Chromosomes. — The chromosomes have separated 

 from each other to a lesser or greater extent and are thrown in 

 a knot in the center of the cell. The chromosomes do not yet 

 have the regular and finished form of V's (Figs. 88-91, 94-97). 



V-MctapJiase. — The chromosomes are in the shape of per- 

 fect F's and are as such thrown on the equator of the central 



