292 



CARL R. MOORE. 



treatment with butyric acid or warm sea-water or cyanide sea- 

 water may be substituted for the hypertonic sea-water, or that 

 both the preliminary and secondary treatments with warm sea- 

 water may accomplish the same results. From inference any 

 agent or combination of agents that cause a quantitative ful- 

 fillment of the reactions lead to the same end. 



When a spermatozoon fertilizes an egg the optimum stimula- 

 tion has been given to the egg, and we assume that the initiatory 

 reactions have been quantitatively complete. But certainly in 

 the initiation by artificial agents some of the eggs will not have 

 been given the optimum conditions and will not have completed 

 their reactions. If we can think in terms of chemical substances 

 we will suppose that part of these have been left uncombined 

 that are yet capable of some reaction with a spermatozoon if it 

 but gain entrance to the egg. Consequently just so far as these 

 fundamental reactions have been incomplete the spermatozoon 

 is capable of asserting its latent stimulus for the activation pro- 

 cesses. That fertilization is not complete in such cases is shown 

 by the very irregular type of cleavage and the small per cent, 

 of swimming larva^ and the poor quality of these, just as in a 

 parthenogenetic treatment the same results are encountered if 

 an exposure above or below the optimum one is given. If how- 

 ever the initiatory agent employed, has been affective enough to 

 cause the production of good membranes (butyric acid), or has 

 resulted in segmentation of the egg, the initiatory, reactive, egg 

 substances appear to have been pretty well used up and so far 

 as these experiments show there seems to be no tendency for a 

 regeneration on the part of an egg of the fertilizable condition. 

 The blastomeres of an egg appear to have no capacity, or at the 

 most very little, to react with a spermatozoon. It has been 

 pointed out above that out of hundreds of these isolated blasto- 

 meres never has one been able to produce a swimming larva, as a 

 result of fertilization; and sections have revealed but one abso- 

 lute case of sperm aster formation after penetration. One 

 activation seems to preclude all others. 



Fertilization appears to be due to an agent, spermatozoon, 

 that initiates development by producing a condition that per- 

 mits of the interaction of certain substances within the egg, 



