230 NEIL S. DUNGAY. 



one and two cell stages were secured in large numbers. Attempts 

 at first cleavage were also seen. Although so few experiments 

 were made by this method that we do not get all the types of 

 abnormality which were produced by the heat and delay, we 

 have a clear indication that more work and better technique 

 would produce very similar results. The work was dropped in 

 order to take up more promising methods. 



4. Alcohol. In experiment 29 of June 29, 1911, the sperm cells 

 were kept in a series of weak alcohols for 35 minutes. The un- 

 fertilized control showed no jelly and no segmentation. The 

 fertilized control was normal. Sperm which had been exposed 

 to the action of 10 per cent, alcohol (made up with sea water) 

 were incapable of producing any effect upon the eggs. 8 per 

 cent, alcohol gave similar results. A few eggs, about 2 per cent., 

 were fertilized by sperm cells which had been kept in 6 per cent, 

 alcohol. Of the 15 eggs which were observed to form jelly, 2 

 did not segment, one divided only once, and the remainder were 

 motile on the second day. Of the motile forms one half were 

 abnormal in some way upon the fourth day. During the course 

 of the whole experiment this culture was greatly retarded in 

 development. Sperm from the 4 per cent, alcohol fertilized 

 25 per cent, of the eggs and, with the exception of a few unseg- 

 mented eggs, all developed the power of motion upon the second 

 day, though they did not develop so rapidly as did the controls. 

 On the third day at least 3 per cent, were visibly abnormal in 

 body form or in setse. The fourth day showed 10 per cent, to be 

 abnormal. Some never formed any setse, some formed weak 

 ones, and some were nearly perfect in this respect. Irregular 

 bunches were often present upon the sides of the segments. The 

 apparent age of the animals in the culture varied greatly. 2 

 per cent, alcohol did not prove to be so effective, for 60 per cent, 

 of the eggs were fertilized and developed with fewer abnormalities 

 than any of the cases given above. 



Other experiments show that sperm cells exposed to weak 

 grades of alchool for a longer time give about the same results 

 as those exposed to higher strengths for shorter periods. Early 

 segmentation stages do not appear to be so much affected as the 

 larval stages, though usually there were at least a few eggs which 



