CHROMATIN DEVELOPMENT AND HEREDITY 



253 



The chromosomes show in many cases the expected forms of 

 rods and hooks. Thickened or round bodies similar to those 

 which Miss Morris identified as Ctenolabrus chromosomes are 

 present, but are very inconstant in size and number (figs. 83 to 

 85). 



In these eggs no trace of the lagging chromatin is to be found 

 when the cells are in the resting stage. The eggs of Menidia, 

 however, also present the same difficulties in recognizing either 

 condensed chromatin or such chromosomal vesicles as occur 

 in Fundulus. Any chromatin eliminated from the nucleus is 

 probably quickly dissolved and absorbed by the egg. 



GENERAL DISCUSSION 



A general statement of the developmental and cytological 

 results observed in the six heterogeneous crosses with which this 

 study is chiefly concerned is given in table 1. 



TABLE 1 



In all of the six crosses the species Ctenolabrus adspersus 

 has been used as one of the parent species, and the list includes 

 three reciprocal crosses. An examination of the tabulated 



