XXVI 



ON THE NATURE OF THE PROCESS OF FERTILIZA- 

 TION AND THE ARTIFICIAL PRODUCTION OF NOR- 

 MAL LARV.E (PLUTEI) FROM THE UNFERTILIZED 

 EGGS OF THE SEA-URCHIN l 



1. FORMER researches had led me to suspect that changes 

 in the state of matter (liquefactions and solidifications) might 

 play an important role in the mechanics of life-phenomena. 

 While studying the absorption of liquids by muscle I found 

 that, to all appearances, a | solution 2 of CaCl 2 favors the 

 formation of solid compounds in the muscle, while an equi- 

 molecular solution of KC1 favors the formation of more 

 liquid compounds. Na ions rank between the K and Ca 

 ions. In these phenomena, however, much depends upon 

 the concentration of the salts. We know that the enzymes 

 of coagulation and liquefaction are greatly influenced in 

 their action by the Ca, Na, K, and Mg ions. Ca favors 

 coagulation, and Mg does the reverse. Between these come 

 the two other ions. In this case also much depends upon 

 the concentration. 



I have made a series of studies on the mechanics of life- 

 phenomena, which will be published shortly in this Journal. 

 I wish now to deal only with one part of these studies, 

 namely, that referring to the nature of the process of fertili- 

 zation. 



I found that in fn solutions 3 of CaCl 2 , NaCl, KC1, and 

 MgClg the segmentation of fertilized eggs of sea-urchins 



1 American Journal of Physiology, Vol. Ill (October 1, 1899), p. 135. 



2 I propose to substitute in the future the -5- solution of NaCl for the 0.7 per 



O 



cent, solution. It is time that we were rid of percentage solutions in physiology. 



3 Approximately the concentration of sea-water. 



539 



