STUDIES IN ARTIFICIAL PARTHENOGENESIS. 19 1 



lead to some coagulation before mitosis can be accomplished. 

 At present all students of artificial parthenogenesis, if they con- 

 sider this coagulation at all, regard it as a secondary result. 

 Thus, some think an increase of oxidations is first produced by 

 all parthenogenetic agents, and that the increased oxidation 

 involves changes which produce coagulation. Others think of 

 the prime cause as an increase of permeability. But it is also 

 possible to believe that the primary effect of all the partheno- 

 genetic reagents is a coagulation effect. This view has had as 

 its adherents, at one time or another, some of the foremost 

 students of artificial parthenogenesis. In his earliest papers 

 on the subject, Loeb occasionally leaned toward coagulation as a 

 possible primary effect, but he soon abandoned the idea to 

 become its vigorous opponent. Delage for many years main- 

 tained that artificial parthenogenesis is the result of a coagu- 

 lation followed by a liquefaction, he considered membrane 

 elevation as one evidence of such a coagulation. At present, 

 however, (Delage and Goldschmidt '13), he favors the Lillie 

 theory of increased permeability as affording a more probable 

 explanation of the facts. Possibly the most vigorous and 

 scientific attempt to support the coagulation theory was that of 

 Fischer and Ostwald ('05). These workers argued from a theo- 

 retical standpoint that all parthenogenetic agents are of such a 

 nature as to produce coagulation. Later Ostwald ('07) retreated 

 from this view and admitted that coagulation might be only 

 secondarily produced as a result of increased oxidation. That 

 all parthenogenetic agents cause coagulation, was denied by 

 Loeb. 1 He pointed out that benzol, toluol, and saponin are 

 not protein coagulants. Since then the theory of Fischer and 

 Ostwald had had no one to defend it. 



The view that I would maintain is that the only physico- 

 chemical effect which all parthenogenetic agents possess in 

 common is the production of a gelatinization or coagulation 

 within the egg. Hence I regard this gelatinization (or coagu- 

 lation) as the direct cause of the initiation of development. 



Leaving theory aside, it is possible to demonstrate that all 

 parthenogenetic agents actually do produce gelatinization or 



1 Loeb, '09, p. 217. 



