1 2O E. G. SPAULDING. 



be accounted for, but if this is done by electrolytic theories, then 

 the existence of osmotic pressure cannot be denied. Lillie, how- 

 ever, neglects its consideration and in this respect his vievv is 

 incomplete. If the necessity for segmentation of the presence 

 of electrolytes in the egg is proven by such data as Lillie has 

 advanced then osmotic phenomena must be also present, and 

 that they play an important part cannot be denied in the face 

 also of the evidence from artificial parthenogenetic methods. 

 Rather, conversely, starting with the known fact of the effective- 

 ness of, e. g-., the osmotic pressure methods, the possibility of 

 these leading to the electrical changes should be shown. The 

 objection may be made that, although present, osmotic pressure 

 may nevertheless be left out of consideration for the reason that 

 it is of low intensity. This objection does not hold good, we 

 think ; for, given a semipermeable membrane and the tendency 

 of surface tension to reach its maximum, the latter will do this 

 until balanced by at least as high a pressure as in the normal 

 surrounding medium, sea water, of the marine forms we are con- 

 sidering. 



It therefore seems possible and even necessary to unite the 

 two views ; to take the position that the electrical phenomena 

 described by Lillie cannot be done away with but, being essen- 

 tial, they can nevertheless, as we have experimental evidence to 

 show, be brought about in a number of different ways, such as 

 amount of water present, action of heat, agitation, etc.; and that 

 they cooperate with the factors we have emphasized in making 

 up the physical and chemical events of cleavage processes. This 

 possible perfect agreement of Lillie's theory with our own, into 

 which all the factual methods have been shown to fit, adds, 

 it seems to us, one more confirmatory element to the synthesis 

 which it has been our purpose to attain. 



The electrolytic methods which have been referred to as the 

 third class which bring about physical changes may therefore be 

 explained from the standpoint of this more complete view. As 

 our factual result we have artificial parthenogenesis produced in 

 Asterias eggs by the action of TV/io HC1 solution (2-5 c.c. + 100 

 sea water) for about one hour, with a subsequent transferral to 

 sea water. Dissociation takes place in the dilute solution used. 



