492 MAX MORSE 



signally applicable here. The recent paper of Ralph Lillie ('12) 

 is suggestive of a manner of approaching the problem from a 

 slightly different point of view. 



3. Experiments with sperm extracts 



The experiments described here concern two things: (1) The 

 repetition of Winkler's ('00) experiments with sperm extracts 

 and (2) the effect of lecithin upon the unfertilized egg. It will 

 be recalled that Fieri ('99) described experiments in which water 

 extracts of spermatozoa were made by simple shaking with sea- 

 water and filtering through filter-paper. Of course the experi- 

 ment is fruitless because the spermatozoa pass readily through 

 the paper. Winkler's experiments were more carefully performed, 

 for he used distilled water as a medium for extracting the supposed 

 'ferment' although of course the use of distilled water, with a 

 decidedly different osmotic pressure from the sea-water, intro- 

 duces a variable wholly apart from any under control which he 

 attempted to obviate by using salt solutions to restore the changed 

 osmotic pressure. He found that when the extract which gave 

 satisfactory results in the cold, is heated to 50°-60°C., no seg- 

 mentation of the eggs results. Such a temperature would not 

 permit a conclusion as to whether there is an enzyme present in 

 the spermatozoon which affects the egg, for such temperatures 

 are fatal to enyzmes of all kinds (Bayliss '08, p. 12) as well as 

 sperm. 



For this reason, I repeated Winkler's work upon both Cerebrat- 

 ulus and Arbacia, by using only that temperature which killed 

 the spermatozoa but no higher, which I found to be in the neigh- 

 borhood of 40°C. This is a degree of heat which is seldom if ever 

 fatal to enzymes and the optimum for many is but a few degrees 

 below (37.5°C). Consequently, by bringing the spermatozoa 

 in their fluid to this temperature in a test-tube and then cooling 

 to 17°C, there is every reason to believe that no enzyme action 

 has been affected, although of course positive proof is wanting. 

 At any rate, in both Cerebratulus and Arbacia, no development in 

 the eggs was observed, although a great variety of concentrations 

 and dilutions were made in both cases. It has been suggested 

 that Winkler's work was really a study in hypertonic solutions. 



