248 ARTIFICIAL PARTHENOGENESIS AND FERTILIZATION 



over the whole egg, contracts and gathers the fat-droplets into 

 one hemisphere of the egg. Hence there arise two phases on 

 the surface of the egg, one of which apparently contains no 

 fat or pigment, while the other obviously contains both. 



This observation led me to consider whether the importance 

 of fat-solvents as well as, in part, that of the alkalies at the 

 maturation of the egg may not perhaps consist in the liquefac- 

 tion of solid layers of fat. In the egg of Heteronereis (of Pacific 

 Grove) there is a confluence of the droplets and a migration of 

 the larger drops and of the pigment mass to one hemisphere of 

 the egg, and this could easily be explained as the effect of 

 surface tension. There is obviously an analogy between the 

 artificial production of maturation and of membrane formation. 

 In both cases, the process of solution of the chorion or of a 

 substance lying at the surface of the egg appears to play a part. 



