PRESENT STATUS OF CHONDRIOSOME PROBLEM. 8 1 



of considerations: the constancy of the chondriosomes in the 

 spermatozoon, the lack of a satisfactory hypothesis as to their 

 significance 1 and the fact that in a number of adequately in- 

 vestigated cases they have been found to penetrate into the egg, 

 render, in my opinion, further research necessary before a decision 

 can be reached. The study of fertilization is indeed a difficult 

 one, especially the investigation of such minute constituents of 

 the spermatozoon amid the huge mass of the egg, but it is of 

 such fundamental importance that the investigator will find in 

 it his reward. 



1 Since the middle piece of the spermatozoon does not change its shape nor its 

 volume in the egg of the sea-urchin, it can apparently not be considered as having 

 the value of a chemical factor, such as postulated by Loeb in his theory of fertili- 

 zation. 



