222 NEIL S. DUXGAY. 



43; 43-7; 43; 43-7; 43: no later records. Samples of eggs 

 from one female, numbered 65.1, 65.2, 65.3, 65.4, and 65.5, were 

 inseminated with heated sperm at the end of n, 12, 13, 15, and 

 16 minutes respectively. In the first four about 95 per cent, of 

 the eggs formed jelly immediately. Sample 65.5 gave about 80 

 per cent, with jelly. All of the above were discontinued. 65.6 

 was inseminated at 2:04 P.M. with sperm which had been heated 

 for 17 minutes. Jelly formation began at once but took place 

 in a gradual manner, some eggs failing to give off jelly until the 

 end of half an hour. Eventually about 60 per cent, formed jelly. 

 Of the eggs with jelly 50 per cent, failed to segment, 15 per cent 

 died before gastrulation, 25 per cent, formed trochophore larvae 

 later than did the controls, and 10 per cent, behaved in a seem- 

 ingly normal fashion. Discontinued before the formation of the 

 larval seta? because all had been preserved. Control of infertile 

 eggs showed only a trace of jelly formation after 18 hours. The 

 inseminated control developed normally. A series of preserva- 

 tions from the experimental culture 65.6 was made at 10 minute 

 intervals, beginning at 2:24 P.M. 



Experiment 63, July 3, 1912, was conducted in a similar manner 

 and furnishes a somewhat fuller record of the later stages. 63.5 

 was inseminated at 10:36 with sperm which had been kept in 

 a warm bath (about 44 C.) for 14 minutes. Over 70 per cent, 

 formed jelly. First cleavage was observed at 12:15 P.M., 7 

 minutes later than in the case of the control series. At 1 :25 

 P.M. the control culture was nearly two cleavages ahead of the 

 experimental culture. About 5 per cent, of the eggs in the 

 experimental culture failed to segment after forming jelly. At 

 8:45 A.M. on the following day the experimental culture was 

 very much less active than the control. About 5 per cent, had 

 died in cleavage stages. 49 hours after insemination the control 

 animals were in excellent condition and were sending out the 

 second set of larval setee. The experimental culture showed 

 clearly that the injury to the sperm cells may cause abnormalities 

 in those eggs which seem to behave normally in the earlier stages. 

 50 per cent, of the developing eggs had not gone beyond a troch- 

 ophore stage. Most of these died soon, though a few continued 

 to live for at least another day without any change except an 



