THE BIOLOGY OF THE CELL SURFACE 



any one common factor; they act either as butyric acid, as 

 strong hypertonic sea-water or as distilled water. That 

 is, the cytolytic agents lack a specific factor, whereas the 

 fertilization-reaction reveals a high degree of specificity, 

 borne equally by the components, egg and spermatozoon. 

 If one adheres to the lysln-corrective factor theory of fer- 

 tilization, one must assume the addition of a specific factor 

 in the spermatozoon imposed upon the nonspecific "for- 

 tuitously combined combinations" of factors, resembling 

 butyric acid, hypertonic sea-water and distilled water. 

 From this point of view specificity would reside only in the 

 spermatozoon, the egg playing no part. We are told that 

 "the lysins of foreign animals can get into cells by mere 

 diflFusion, while the lysins of the same species can not get 

 into the egg by diflFusion. Only through the motile power 

 of the living spermatozoon which acts as a carrier can the 

 fertilizing lysin of the animal's own species get into the 

 egg."^ Here the author of this theory reveals the failure of 

 well-known physico-chemical agents to act as substitutes 

 for that "mysterious complex" called the "living sperma- 

 tozoon." The high purpose, to transfer the problem of the 

 initiation of development of the animal egg from the realm 

 of morphology to that of physical chemistry^ is frustrated 

 at a most crucial point. It is, therefore, needless to discuss 

 the problem of specificity further in this connection. 



The order of the two phases of the fertilization-process 

 is constant in a normal egg; always the external (ectoplas- 

 mic) changes come first and the internal (mitotic) come 

 second. Never does a normal Qgg exhibit the phenomena 

 of the internal phase before the ectoplasmic changes charac- 

 teristic of its fertilization-process have taken place. As I 

 have already pointed out, in the experimental partheno- 



1 Loeb, 1913. 

 - Loeb, ibid. 



234 



