ORIGINAL Meruop oF ARTIFICIAL PARTHENOGENESIS 171 
into Delage’s mixture which is merely a hypertonic solution 
rendered alkaline by an excess of NH,OH. It is obvious that 
in this case the solution of Delage could have produced only 
the corrective effect typical for hypertonic solutions. The addi- 
tional NH,OH could do no good, and probably did some harm. 
The larvae which were produced by this method did not de- 
velop as far as those produced when the simple hypertonic sea- 
water, as I use it, was added. 
Delage has drawn the conclusion that in his experiments 
the tannic acid causes a coagulation and the alkali a liquefac- 
tion, and that development is due to an alteration of coagula- 
tions and liquefactions. Since we have shown in this and the 
previous chapter that the mere treatment of the eggs with an 
alkaline hypertonic solution causes the production of parthe- 
nogenetic plutei, and since it can be demonstrated that any 
hypertonic solution containing the proper amount of NH,OH 
or any other weak base acts as well as Deiage’s solution, the 
conclusion he draws from his observation becomes untenable. 
