178 EDWIN J. COHN. 



curred only in weakly alkaline solution, since sperm were "in- 

 jured" in more concentrated alkaline solution. 



From these and other observations Koelliker came to believe 

 that the nourishment and therefore the length of life of the 

 spermatozoon after it is liberated from the testes is dependent 

 only upon the material of which it is constituted. "Eher ware 

 daran zu denken, ob nicht vielleicht die Korper der Samenfaden 

 sich zu den Faden selbst verhalten, wie eine Zelle zu ihren Wim- 

 perhaaren, und dieselben aus dem in ihnen enthaltenen reich- 

 lichern Material ernahren, eine Vermuthung, die jetzt, wo ich 

 zeigen kann, dass die Samenfaden aus den Kernen der Samen- 

 zellen sich bilden, wohl ausgesprochen werden darf. Zu erfor- 

 schen ist auch noch, ob die Samenfaden bei ihren Bewegungen 

 elektrische Strome entwickeln, und ob sie nicht, so lange sie sich 

 bewegen, CO2 abgeben, wahrend sie O aufnehmen, Verhaltnisse, 

 iiber die ich vielleicht spater berichten kann" (Koelliker, A., 

 1856, p. 245). 



On the basis of observations of a quite similar kind Gemmill 

 (1900) came to exactly the opposite conclusion. He observed 

 that "the term of vitality of spermatozoa varies according to the 

 degree of their admixture with sea water" (Gemmill, J F., 

 1900, p. 170) and correctly concluded that "mixing with sea- 

 water stimulates the activity of movement of the spermatozoa, 

 which become the more active the better they are mixed with 

 pure sea water. Under these circumstances, their store of energy 

 will be the sooner exhausted" (Gemmill, J. F. 1900, pi. 169). 

 Gemmill was of the opinion, however, that if sperm lived longer 

 in more concentrated suspensions it was because they there re- 

 ceived more nourishment, for he goes on to say: "On comparing 

 the movements of spermatozoa in different mixtures, one finds 

 that the difference of activity is not sufficiently marked to ac- 

 count for the very early loss of vitality of spermatozoa in the 

 weaker mixtures simply in terms of exhaustion of energy. I am 

 inclined to believe that the other factor above noted, namely, 

 the dilution of the nutritive medium by the addition of sea water, 

 is the more important cause. An interesting sidelight on this 

 question is afforded by some facts which will be given later 

 regarding the keeping alive of spermatozoa by artificial nutri- 



