Self-Fertilization Induced by Artifidal Means. 157 



A few experiments were carried out in order to see if the sperm 

 made active by the alcohol, would self-fertilize the eggs when 

 it would not do so without the stimulus. Here, as in the preceding 

 series, the same lettering will be used in the tables. A^ self- 

 fertilized in sea-water, A^ self-fertilized in alcohol-solution, A'' 

 crossed in alcohol-solution. 



A^ B'^O 



A^ [Alcohol] few B" [Alcohol] several 



A" 20 B^ 50 



In this experiment while no eggs were self-fertilized in sea- 

 water, a few or several (the percentages were not recorded) were 

 self-fertilized in alcohol, but even more developed in the crossed 

 lots. 



In another experiment only one individual was used. The 

 eggs, self-fertilized in sea-water, did not segment, but 10 per cent, 

 did so in a 3 per cent, soluton of alcohol, and 50 per cent, in a 5 

 per cent, solution of alcohol. 



Solutions of ammonia gave similar results. Sperm and eggs 

 were mixed together in very dilute solutions of ammonia. Many 

 eggs divided and of these most appeared, from their method of 

 division into several cells at once, to be polyspermic. Some of 

 the sperm from the last lot was added to eggs in sea-water. 

 Fewer eggs were fertilized, but several that were fertilized were 

 polyspermic. Eggs (not separated from their own sperm) were 

 crossed in ether. All of these were polyspermic. Another set 

 gave almost identical results. 



It is clear from these experiments that those solutions that 

 make the spermatozoa more active often induce fertilization of 

 the eggs, when such a fertilization does not take place without 

 the use of the solutions. The activity of the sperm and the fer- 

 tilization of the egg appear to be directly connected. This point 

 will be more fully discussed later. 



EXPERIMENTS WITH MOLGULA. 

 On each side of the body of Molgula there is an ovary sur- 

 rounded by a testis. It is very easy to open the central cavity 

 of the ovary, and remove the eggs without cutting the testis. 



