STUDIES IN GENERAL PHYSIOLOGY 



V. SOME REMARKS CONCERNING THE NATURE OF THE PROCESS 

 OF FERTILIZATION 



The facts of the preceding section force us to transfer the 

 problem of fertilization from the realm of morphology into 

 that of physical chemistry. There is certainly no reason 

 left for defining the process of fertilization as a morphological 

 process. The morphology of the spermatozoon itself becomes 

 of secondary importance as far as the process of fertilization 

 is concerned. 



The spermatozoon not only starts the development of non- 

 parthenogenetic eggs, but it is also the bearer of the heredi- 

 tary qualities of the male. From our experiments it becomes 

 evident that these two functions of the spermatozoon are 

 not necessarily bound together, for nobody would assume for 

 an instant that the hereditary qualities that are carried by 

 the spermatozoon could be imparted to the egg by a change 

 in the inorganic constituents of the sea-water. We have 

 learned to attribute the different activities of a cell to 

 different enzymes. We must in future consider the possible 

 or probable separation of the fertilizing qualities of the 

 spermatozoon from the transmission of hereditary qualities 

 through the same. 1 



The plutei produced from the unfertilized egg resemble 

 closely in every regard those produced from the fertilized 

 egg. The latter in many cases live longer than the former, 

 but even this was not so in every case, and it is not impos- 

 sible that in further experiments parthenogenetic plutei with 

 a greater duration of life will be produced. The only 

 difference between parthenogenetic and normal blastul?e is 

 that the latter rise to the surface of the water, while the 

 former do not. One might think that this was due to the 

 influence of the MgCl 2 solution on the egg. This is, how- 

 ever, not the case. Eggs that had been in such a solution 



1 LOEB, Biological Lectures, Woods Hole, 1899, Ginn & Co., Boston. 



