472 L. V. HEILBRUNN. 



cited above it was pointed out that coagulation occurred after 

 26 minutes exposure to ether. In this same experiment some of 

 the eggs were removed from the ether solution after an exposure 

 of 24 minutes and placed in normal sea-water. Others were 

 removed from the ether after an exposure of 28 minutes. Some 

 of the eggs exposed to ether 24 minutes were inseminated, 

 following an interval of 18 minutes after removal from the ether, 

 and some of the eggs exposed 28 minutes were inseminated 

 following an interval of 14 minutes after removal from ether. 

 None of the inseminated eggs showed any signs of development. 

 As a matter of fact both the inseminated eggs and those not 

 exposed to sperm went through the same series of degenerative 

 changes. All of them disintegrated by breaking up into small 

 globules. 



Thus it is obvious that following the coagulative action of 

 ether there is no recovery. The same sort of experiment was 

 repeated a number of times always with the same result. If 

 eggs are to recover from ether treatment they must be removed 

 from the ether solution some few minutes before coagulation 

 has begun. 



The discussion so far has been concerned only with conditions 

 in unfertilized eggs. In fertilized eggs the effects of ether are 

 even more pronounced. Let us consider a sample experiment. 

 In the following account many details of observation are omitted. 



July 22 (Temp, about 24). Eggs were fertilized at 3.35 P.M. Fifteen min- 

 utes later, at 3.50 P.M., they were centrifuged at the usual rate for 50 seconds. 

 No zones appeared (control unfertilized eggs showed a hyaline zone about M of 

 the distance along the egg axis after 30 seconds treatment). At 3.52 P.M. some 

 of the fertilized eggs were placed in 2}^ per cent, ether in sea-water in a glass- 

 stoppered weighing bottle. At 3.55 P.M. a centrifugal test for 60 seconds showed 

 only a thin streak for a hyaline zone in the control untreated fertilized eggs. At 

 4.27 P.M. the etherized eggs when centrifuged for 20 seconds showed a hyaline 

 zone extending more than a third of the distance along the egg axis. At 4.31 P.M. 

 a test of the etherized eggs for 15 seconds showed a similar zone extending about 

 one third of the axis, and at 4.33 P.M. a 10 second test showed a hyaline zone 

 extending through approximately one fourth of the egg. 



From this experiment we can conclude that when fertilized 

 eggs are placed in 2> per cent, ether at a time when the viscosity 

 of their protoplasm is at its height, the ether reduces the viscosity 

 to less than one sixth of its original value. Another experiment 

 of the same sort may also be cited. 



