542 FRANK R. LILLIE 



with agglutinated sperm masses. The alkahs were used in 

 concentrations of N/2500 and N/5000. 



Though no chemotatic reaction takes place, yet an interesting 

 reaction may be procured by injecting a drop of N/5000 KOH into 

 a sperm suspension made in 1/100 dilution of saturated CO2 

 sea-water. The sperm in this are nearly or quite paralyzed, and 

 will not of course react to an injected drop of 1/100 CO2. But if 

 a drop of N/5000 KOH be injected into such a suspension beneath 

 a raised cover glass, motility of the spermatozoa returns at a short 

 distance from the margin of the introduced drop, due evidently 

 to neutralization of the acid, and aggregations of the active sperm 

 may form outlining the KOH drop a certain distance from the 

 margin. This experiment furnishes at once an interesting demon- 

 stration of recovery from CO 2 narcosis, and of the nature of the 

 contrast between the acid and alkali reaction of the spermatozoa. 



5. Reactions to other substances 



It lay entirely outside of the scope of this work to attempt an 

 exhaustive analysis of the behavior of the spermatozoa with 

 reference to chemical substances. The investigation was under- 

 taken to analyze the relations of the behavior of spermatozoa 

 to fertilization; and when the principle of chemotaxis was once 

 demonstrated, and the relation of this chemotactic reaction to the 

 very striking aggregation reaction, it seemed better to turn at 

 once to the subject of the behavior of the spermatozoa towards 

 eggs and egg-secretions of the same species. It may be remarked 

 incidentally that tests with alcohol and ether gave negative 

 results, that is, no evidence of positive or negative chemotaxis 

 was found. In some cases there was slight indication of ring 

 formation near the margin of an introduced drop of 5 per cent 

 alcohol or ether in sea-water, which may indicate a stimulating 

 effect of the spermatozoa at an optimum concentration, but which, 

 in the absence of a clear margin external to the ring cannot indi- 

 cate chemotaxis. 



