226 WHAT 18 LIFE 



according to Overton) as well as of animals, from 

 echinoderms up to the frog."^^ Again: "The fact 

 that the method which causes artificial partheno- 

 genesis in the eggs of many animals acts in the same 

 way in the case of the eggs of plants indicates the 

 identity of this process in all living organisms."^* 



Concerning the egg, all the many successful experi- 

 ments that have been made on artificial partheno- 

 genesis, have demonstrated that fertilization of the 

 egg can be effected by any means that can cause 

 adequate "chemical" changes in the "ripe" egg. 

 Anything that initiates certain specific changes in 

 the egg, induces formation of the fertilization mem- 

 brane and the development of the egg into an embryo. 

 Experimenting on nereis, F. R. Lillie found that 

 fertilization of the egg can be effected by a spermato- 

 zoon from which the tail, the middle-piece and part 

 of the head has been removed. 



As stated before, the mere piercing of the frog's 

 egg resulted in the development of the egg and the 

 production of an embryo that grew to maturity. 

 Various physicochemical means have been success- 

 fully employed to cause the fertilization (activation) 

 of the eggs of a variety of forms. Further, perhaps 

 most interesting of all, the fertilization (activation) 



*' The Organism as a Whole, 123. 



** Artificial Parthenogenesis and Fertilization, 279. 



