FERTILIZATION ON PARTHENOGENESIS. 155 



sperm or egg in their union and further behavior following 

 insemination, after artificially induced membrane production. 

 The fundamental limiting factors are bound up in cortical, 

 physical phenomena and these being entirely removed, the nor- 

 mal processes should go on unmodified. 



We should naturally expect in instances of this kind: (i) Re- 

 activation of the egg; (2) penetration of the spermatozoon; 

 (3) normal development. 



(i) has already been considered and proven to the contrary. 

 Sperm are active, come in contact with eggs that have been 

 entirely deprived of their membranes yet they never prove 

 themselves capable of inducing the formation of a new membrane. 

 The lysin-like substance fails to act. (2) will be considered from 

 a study of sections while (3), like (i), has been proven negatively. 

 These eggs do not develop in response to sperm but disintegrate 

 as readily, or more so, than do eggs possessing membranes. If 

 sperm should enter these eggs, and there is nothing in the con- 

 ception of this theory to indicate that it is not so, the spermato- 

 zoon should exhibit its corrective effect and allow the eggs to 

 develop normally. If then sperm are found within these eggs 

 which give no external indications of development every postu- 

 late of the theory will have been disproved and consequently 

 it will have to be discarded. 



The facts already presented however find a ready interpre- 

 tation in terms of the fertilizin hypothesis. Since activation 

 has already been once accomplished, through butyric acid, 

 further influence toward development by means of sperm is 

 entirely negative. From the postulates of this theory we should 

 not expect (i) reactivation; we may or may not expect (2) pene- 

 tration of spermatozoa and we do not expect (3) further develop- 

 ment after insemination. 



(i) and (3) need not here be further discussed; in reference 

 to (2), penetration of a spermatozoon is not the point of greatest 

 importance but rather the question of a reaction between egg 

 and sperm. We do not know all the factors involved in pene- 

 tration. Whether or not the spermatozoon is carried into the 

 eggs in a purely passive state or is itself actively engaged in the 

 process will not be discussed at this point. Of greater significance 



