420 Ralph S. Lillie 



the period of warming — probably to an even greater degree, since 

 the above results on membrane-formation (pp. 381, et seq.) indi- 

 cate a much higher temperature-coefficient of acceleration for such 

 processes under the conditions prevaihng in the cell. Indications, 

 then, seem to point to an acceleration of hydrolytic processes, 

 combined with a repression of oxidations, as an important con- 

 dition in the initiation of development in these eggs. That hy- 

 drolyses are in fact accelerated seem to be indicated by the condi- 

 tions of the membrane-formation; this event occurs quite normally 

 in the cyanide solution; it appears to be dependent on a hydrolysis 

 which is greatly accelerated by a rise of temperature; and presum- 

 ably other hydrolyses in the egg would be similarly affected by 

 the same change of conditions. Membrane-formation seems to 

 afford a clear proof that certain processes, not dependent on oxida- 

 tions, are markedly accelerated by momentary warming, and that 

 certain critical changes in the developmental capabilities of the 

 egg-protoplasm may result from such momentary acceleration. 



Naturally it is impossible for eggs treated as above to develop 

 while remaining in the cyanide solution; the transfer to oxygenated 

 sea-water is indispensable. This transfer however need not be im- 

 mediate. It is possible to keep eggs, after warming under the above 

 conditions, in cyanide sea-water for a certain not too prolonged 

 period before transfer to sea-water. No visible change occurs 

 during the stay in the cyanide solution, but on transfer to normal 

 sea-water development proceeds normally. Indeed, under cer- 

 tain conditions such after-treatment with cyanide has proved 

 highly favorable to development as the following experiments 

 illustrate: 



In these experiments the eggs, after remaining for a certain 

 time in cyanide-containing sea-water, were warmed momentarily 

 as above and brought to normal temperature in that medium; then 

 after an interval they were returned to normal sea-water. A cer- 

 tain stay in the cyanide solution after warming proved in every 

 case decidedly favorable. 



