40 ARTIFICIAL PARTHENOGENESIS AND FERTILIZATION 



The many researches of Hoyer next aimed at ascertaining 

 what was the nature of the acid which is formed in the seed 

 itself and conditions the sudden increase in the hydrolysis 

 of the oil in the germinating seed. It is found to depend 

 mainly upon lactic and carbonic acids, together with a relatively 

 small amount of acetic and formic acids. There occur there- 

 fore two fundamental processes in the conversion of the oil in 

 germination. One process is the fermentative production of 

 acids: lactic, carbonic, acetic, and formic; the second process, 

 which depends upon the first, is the "activation" of the lipolytic 

 enzyme through the acid produced in the seed. 



Investigations with the acids produced in the seed itself 

 elicited the fact that these acids are able to produce the fat- 

 splitting effect in the castor bean. One fact, which is of bio- 

 logical importance, may be mentioned here. If Hoyer chose 

 for his investigation a castor bean that had hardly begun to 

 germinate, and cut it in half (after washing it), it appeared that 

 the oil-splitting enzyme had a weaker effect in the half of the 

 seed which contained the embryo than in the half separated 

 from the embryo. In well germinated seeds there was prac- 

 tically no more ferment present. "In the life history of the 

 castor bean, the ferment becomes inoperative after the per- 

 formance of its fat-splitting function in the same proportion 

 as the castor oil is prepared for the growth of the embryo." 1 



These investigations give us an idea of the complicated 

 character of the processes in the development of the embryo. 

 The taking-up of water leads to a process of hydrolysis in the 

 seed, of which the end-products are certain acids lactic and 

 carbonic. These acids serve, according to Hoyer's description, 

 for the "activation" of the lipase contained in the castor 

 bean. As in all analyses of life phenomena, we are here too 

 dealing with a catenary series of reactions. It seems that in the 

 sea-urchin S. purpuratus also a sudden increase in the acid 



1 Hoyer, Ber. d. deutsch. chem. Ges., XXXVII, 1436, 1904. 



