1886.] 



Seed which accompany Germination. 



467 



it brings about not only in the course of its action on fibrin, but also 

 on the aleurone or proteid reserve material in the seed itself. 



The method which I used in the investigation was somewhat 

 different from that of v. Gorup-Besanez. As Krauch claimed that 

 the biuret reaction obtained was due to some proteid in the digestive 

 extract used, and as the vegetable peptones found in the seed of the 

 lupin do not dialyse, while true peptone does so readily, I carried on 

 my digestions always in carefully tested tubes of dialysing paper, so 

 that the fluid outside the latter might enable me to see if peptone 

 were really formed or no. 



Seeds of Lupinus were germinated for about a week, till they had 

 protruded a radicle of about inch in length ; they then gave an acid 

 reaction to litmus-paper. They were divested of their coats, the 

 radicles removed, and the cotyledons ground. The resulting powder 

 was extracted with glycerine, and the extract dialysed till no trace of 

 any crystalline bodies that had been formed during the germination 

 could be detected in the dialysate. No trace of peptone or other 

 body giving a biuret reaction passed the dialyser, even after a week's 

 exposure. The extract was then acidified with HC1 to the extent of 

 0'2 per cent., put into a fresh dialyser, some swollen-up boiled fibrin 

 added, and the dialyser put into a beaker and surrounded with 0'2 

 per cent. HC1. It was then left at a temperature of 40° C. Control 

 experiments, some with boiled digestive extract, some with 0*2 per 

 cent. HC1 only, were carried out side by side with the others. 



The process of digestion was very slow, the time taken up being 

 very much more prolonged than is the case with the gastric or 

 pancreatic ferments. After some time, however, the dialysate in the 

 beaker containing the tube in which the unboiled extract of the 

 cotyledons had been placed gave a very marked biuret reaction, and 

 after concentration it deposited crystals of leucin. The other dia- 

 ly sates contained no peptone or crystalline body. 



I repeated the experiments many times with varying quantities of 

 the extract of the cotyledons and with varying amounts of fibrin, 

 and in all cases I was able to see that a proteolytic ferment was present 

 in the germinating seed, and that it formed not only peptone but 

 leucin, behaving like pancreatic rather than gastric juice. In this 

 latter particular I am somewhat at variance with v. Gorup-Besanez, 

 who says he was not able to see that the decomposition of the fibrin 

 proceeded beyond the stage of peptone. 



Further investigations into the condition of the action of the 

 ferment showed that it worked best in a medium acidified to the 

 extent of 02 per cent. HC1 : that the temperature most favourable for 

 its working was 37 — 40° C, that its activity was somewhat impeded 

 by the presence of excess of neutral salts, and that it was speedily 

 destroyed by contact with alkalis, even to the extent of 1 per cent. 



