STUDIES OF FERTILIZATION 559 



of its relatively small amount the new membrane was formed 

 close to the egg. The implied fact that the experiment failed 

 after a short time supports my theory of the function of fertilizin, 

 and the stated result is not at all inconsistent with my views. 

 According to my point of view the possibility of superimposing 

 fertilization on parthenogenesis would persist so long as a sufficient 

 quantity of fertilizin remained unbound, i.e., so long as the 

 reaction was incomplete. "* 



The non-fertilizable character of such eggs implies on my theory 

 an absence of free fertilizin. This condition obtains, as the 

 following experiments show: 



Experiment August 26, 1913: A quantity of fresh Arbacia eggs 

 Avere taken and some were set aside in a test tube as control (0.14 cc. 

 when settled). The balance were concentrated in 3.4 cc. sea-water. 



3:47 P.M. The latter were then added to 25 cc. butyric acid in sea- 

 water made by adding 2.8 cc. ^ butyric acid to 50 cc. sea-water. 



3:47 1/2 P.M. Half of the eggs with acid were poured into 1500 cc. 

 sea-water in crystallization dish A and stirred up to stop the action of 

 the acid. 



3:48 P.M. The remainder were poured into 1500 cc. sea-water in 

 crystallization dish B and stirred up. B was over-exposed and the eggs 

 agglutinated heavily. In A there was no agglutination and nearly 

 all of the eggs formed fine membranes. The jelly was absolutely all 

 gone owing to the action of the butyric acid, so there was no need to 

 shake them. 



The eggs in A and B were then concentrated, and placed in graduated 

 tubes similar to the control. When settled there was 0.3 cc. eggs in 

 each, estimated to be at least 4 times as many as in the control tube 

 when allowance is made for the bulk of the jelly in the control. All 

 were then submitted to successive washings with tests as shown in 

 table 7, p. 560. 



Thus the A eggs, with m-embranes formed, came negative in 

 four washings, at least as rapidly as fertilized eggs, whereas the 

 unfertilized control with fewer eggs was still showing an aggluti- 

 nation strength of about 10 (control 4, 1/1 — 50 seconds). There 



^ The essential problem is whether fertilization is of the nature of an irrever- 

 sible chemical reaction, as I claim, or is merely a physical surface eflfect. Al- 

 though this question has been investigated a good deal, it is still far from being 

 definitively settled. The students of artificial parthenogenesis take the latter 

 point of view generally. 



