234 NEIL S. DUNGAY. 



of the work since it is in line with the work upon Nereis and since 

 some of the features here described have not been previously 

 recorded. 



Experiments were carried out by inseminating eggs with sperm 

 which had been subjected to injurious conditions for a longer 

 or shorter time. The injurious agents used were (a) sea water 

 concentrated by boiling; (b) sea water diluted with distilled 

 water; (c) sea water with from one to twelve per cent, of alcohol 

 added; (d) sea water slightly acidified with HC1; (e) keeping 

 the sperm cells from 6 to 24 hours after removal from the body; 

 and (/) combinations of the above. 



In a general way these methods of treatment did not give 

 specific effects but produced very similar results, although the 

 intensity of the effects varied as was to be expected. In one 

 case the controls were nearly as abnormal as the experimental 

 cultures. But, taking the experiments as a whole, there can 

 be no doubt as to the great differences to be found between the 

 controls and the experimental series. 



The abnormalities produced by inseminating normal eggs with 

 injured sperm may be briefly reviewed. In a few cases in which 

 the sperm cells were exposed to extreme conditions, insemination 

 gave a number of cases of membrane formation without develop- 

 ment. Cleavage was found to be extremely irregular in some 

 cases, producing fantastic forms, such as ciliated plates and rows 

 of cells. The more normal cleavage was also found to be ir- 

 regular but it is difficult to say that it was more irregular than it 

 sometimes is in normal cultures. The development of the experi- 

 mental series was often found to be retarded, especially after 

 late cleavage. The early cleavage was not affected so much, 

 though occasional indications of a slight retardation were 

 observed. Curiously enough, in some of the experiments using 

 alcohol, the experimental material was observed to be one or 

 two cleavages ahead of the controls in the early segmentation 

 stages, though the difference was soon in the other direction, if 

 any was apparent. Prismatic forms were often observed in the 

 controls when the experimental cultures were chiefly in the 

 blastula stage. The death rate was much higher in all of the 

 experimental series, the whole culture sometimes dying in various 



