40 



harmony with the existing theories ooncernlng the chromoaomes? 

 In all other cases of fertilization the nucleus with its 

 chromosomes or at least Its chromatin is considered the essen- 

 tial thing; the bearer of the paternal qualities to the egg. 

 The part that they play in the theories concerning heredity 

 is too Important and useful to be lightly discarded. But, 

 granting all that is claimed for the chromosomes, we are never- 

 theless face to face with the fact that in most cases they 

 disappear during the telophase and are reformed in the next 

 prophase of cell division. Between the miotic divisions they 

 can be followed from one spindle to the next and in some other 

 oases some Investigators have claimed to have been able to ob- 

 serve the continuity of Individual chromosomes from one divi- 

 sion of the cell to the next one. But these are exceptions. 

 The problem of the origin of the chromosome is a real problem. 

 For many reasons, in our final analysis, we must go back of 

 the chromosome. So without attacking the proposition that 

 chromosomes are the means for distributing the hereditary 

 elements at the time of division, we may take up the question 

 of the origin of the chromosome before division. 



The phenomena described in this paper force us to con- 

 sider this question if we are to bring the facts concerning 

 fertilization in this crab, in line with existing theories. 

 Does any of the chromatin from the nucleus of the spermatid 

 enter the egg"? We have shown that it is the substance in 

 the wall or in the cavity of the capsule that enters and 

 fertilizes the egg' Now is there any evidence that the chrom- 

 atic substance in the nucleus is transferred to the capsule 



