EFFECTS OF ALCOHOL ON GERM CELLS OF FUNDULUS. 403 



followed out, the high percentage of sub-normals resulting seems 

 to suggest that this is a factor that should at least be carefully 

 controlled, and the effects they have reported as being due to the 

 toxic action of the methylene blue on the sperm may very prob- 

 ably have been due in considerable part to the action of the 

 methylene blue added with the sperm upon the eggs themselves. 

 While only a low percentage of the control eggs developed in 

 this experiment on account of the delayed fertilization a very 

 striking abundance of subnormal individuals were produced in 

 the methylene blue series and no such specimens were recorded 

 in the control. This fact would seem to indicate in a positive 

 way the effects of such solutions on the development of the eggs. 

 The eggs of Fundulus are very probably much more hardy and 

 resistant to all treatments than are those of Gobius, judging from 

 the experiments reported in the literature on the two forms. 



DISCUSSION. 



The results reported in this paper seem to lead to rather definite 

 conclusions. One of these is that the period in the egg prior to 

 fertilization is a critical one. Dosages of alcohol which are com- 

 paratively negligible in their action an hour after fertilization 

 produce marked effects at this earlier period. Also the period 

 very shortly after fertilization seems another time at which the 

 egg is more susceptible to injury. 



In analyzing results such as these one is impressed with the 

 number of factors involved. Different eggs at the same period 

 in their development differ in their resistance to the same sub- 

 stances in solution. A lethal dose for one is comparatively slight 

 in its effect upon another. A part of this results no doubt from 

 the differences in permeability of the individual eggs in the lot 

 involved due to their slightly different metabolic or develop- 

 mental states. As a consequence more of the toxic substance 

 passes through the membranes of certain eggs to affect their 

 protoplasmic content than through the membranes of others. 



Just before fertilization, the maturation processes are in 

 operation in the egg. Immediately after fertilization these are 

 being completed, and the male and female pronuclei are near 

 the surface of the protoplasmic disc of the egg. The effect of 



