FERTILIZATION ON PARTHENOGENESIS. 



173 



TABLE V. 



VI. DISCUSSION. 



In presenting the results obtained during the two previous 

 summers, the writer has employed largely the terminology of 

 the fertilizin hypothesis; no other theory seems capable of 

 offering an explanation of the facts as they have been revealed 

 by experiments. We have seen in Section III. that the lysin 

 theory of fertilization has been entirely disproved by the very 

 mateiial and methods that were used in formulating the hypo- 

 thesis. On the other hand all the results obtained find a ready ex- 

 planation in terms of the fertilizin hypothesis. We have pre- 

 viously noted the quantitative aspects of fertilization in the 

 case of the fertilization curve after butyric acid parthenogenesis 

 (Sec. III.). Wherever there is development, certain substances 

 within the egg have been activated either artificially or by a 

 spermatozoon. 3 If the activation has been initiated by a sperma- 



1 Control for freshness of sperm with unknown strength of fertilizin 60 sec. 

 reaction. 



2 Control for freshness of sperm with unknown strength of fertilizin 70 sec. 

 reaction. 



3 If we do not assume that the egg contains all the essentials for development 

 and that these are started in their piocesses by various activating agents, we 

 have no explanation for parthenogenetic development, normal or artificial. 



