530 FRANK R. LILLIE 



(4), (5), (6) and (7) came from an experiment with the same sam- 

 ple of sperm. 



The sensitiveness to ether is essentially the same, though the 

 sperm did not aggregate even at 0.33 per cent. The chemotaxis 

 experiments with ether indicate a possible stimulation of the 

 sperms at an optimum concentration (see beyond). 



As stated before, no attempt was made to carry the analysis of 

 the relation of activity of the spermatozoa to known chemical 

 substances very far. Experiments on chemotactic and other 

 behavior phenomena of the spermatozoa were in progress at the 

 same time, and the determinations already given seemed fairly 

 adequate for the purposes of analysis. 



6. Sensitiveness of spermatozoa to hypo- and hyper-tonicity 

 of the medium 



As regards the sensitiveness of spermatozoa to hypo- and 

 hypertonicity of the medium, the following determinations may 

 suffice : 



August 18, 1911. Sperm of one male; one drop mixed in each 

 of the following solutions, with results noted: 



(1) 5 cc. sea-water + 2.5 cc. distilled water. The sperm are fairly active, but 

 no aggregations form. 



(2) 5 cc. sea-water + 1 cc. distilled water 1 . ft ' ' t ■ 



(3) 5 cc. sea-water + 0.5 cc. distilled water \ r++i k ++ • a ' 



(4) 5 cc. sea-water J 



(5) 5 cc. sea-water + 1 cc. 5/2 N NaCl; sperm paralyzed 



The spermatozoa will thus stand considerable decrease in 

 osmotic pressure without much modification of activity. But 

 increase in osmotic pressure induced in the experiment by addi- 

 tion of NaCl and in others by KCl, CaCL2 or MgCl2, rapidly 

 paralyzes. The addition of this amount of KCl paralyzed 

 every sample of sperm used and its effect is undoubtedly toxic ; 

 but some samples of sperm exhibited considerable, though 

 decreased, activity, when the other salts were used. 



