EFFECTS OF INJURY UPON SPERM. 22Q 



budding. About 4 per cent, of the eggs were in a 2-cell stage of 

 apparently normal form. A few trochophores, not at all active, 

 were revolving feebly with a lateral displacement of perhaps 

 twice their own diameter. They were abnormal in shape and 

 appearance and though no cilia could be seen they were certainly 

 present since the animals were motile. The whole culture died 

 without developing farther. Other experiments gave similar 

 results or produced fewer abnormalities in early development and 

 lived to produce malformed larvae. 



Since on one day sperm which had been kept for 30 hours 

 would cause most of the eggs in a culture to develop and upon the 

 following day sperm only half as old might have no effect it 

 seemed to be desirable to produce more uniform conditions for 

 keeping the sperm. Accordingly the sperm cells were placed in 

 an ordinary refrigerator in which the comparatively low tem- 

 perature did not fluctuate so much as did that of the outer air. 

 The best results were secured by using the sperm on the third 

 day. By testing out the contents of a vial at intervals during 

 the day it is possible to determine the proper time for starting 

 an experiment. About 40 cultures obtained in this way have 

 been under observation and have given reasonably uniform re- 

 sults. All of the types of abnormal development described 

 above under the head of heat were repeatedly found in this set 

 of experiments. The results given by this set of experiments 

 are very convincing to one who was able to follow the material 

 closely. It is not known definitely whether the injury to the 

 sperm was produced by toxic bacterial products, by the accumu- 

 lation of metabolic products, or by the gradual weakening of the 

 cell by its own metabolism. Whatever the cause, I have no 

 doubt that the effects produced were brought about by insemina- 

 tion with weakened sperm cells. 



j. Fresh Water. Three experiments were made in which the 

 sperm cells were placed in dilute sea water or in distilled water 

 for short periods of time. Sperm from mixtures containing more 

 than 20 per cent, of sea water produced normal development. 

 The results produced by lower percentages of sea water and by 

 distilled water were variable, some normal larvae appearing in 

 cultures in which most of the eggs failed to segment. Permanent 



