i8 2 



Edmund B. Wilson 



smaller than the others. One of these, always central in position, 

 is evidently the m-chromosome bivalent. Of the remaining six, 

 one is in most cases decidedly smaller than the others a relation 



a 



f 



m 



n 



FIG. 12 



25-chromosome forms, three supernumeraries 



a, b, first polar, term., No. 34; c-g, spermatogonial groups from same individual; h, term., No. 38. 

 ovarian group; i-k, ovarian groups from term., No. 27, with two large supernumeraries and one small; 

 /, gran., No. 58, ovarian groups, three large supernumeraries. 



m, n, o, first division, p, second division from gran., No. 54, with three or four supernumeraries. 



of which the constancy is attested by the nine figures given of this 

 division. It is evident that in this individual there are four large 

 supernumeraries and one small; and although nospermatogonia 



