52 



There is still another remarkable thing to be mentioned in this 

 connection; it has been observed by Enriques 37) (p. 11), 

 where he says: „Del resto, il succo gastrico non putrefa o 

 putrefa soltanto dopo molto tempo, anche senza nessuna precau- 

 zione, certamente a causa della sua acidita". The same thing 

 proved to be true for extracts of the retia mirabilia. 



This fact shows a remarkable analogy with the results of 

 Biedermann on the gastric juice of the snails. I have made 

 the same observation repeatedly on samples of digestive juice, 

 as used for the experiments described on p. 30 and 34. They 

 never had that hideous smell of decaying marine material, the 

 remainder of these samples were left standing in the room for 

 more than a week, they were yet fresh at the end. As the 

 paper of Enriques, who states that it is due to acidity, came too 

 late to my attention I could not test for lactic acid in my material. 



In one point I came to conclusions different from those of 

 Biedermann, The acid mentioned in the preceding chapter 

 was formed in an autolysate in the presence of toluene. The 

 same was the case in Lindemann's experiments. Bacterial action 

 seems to be excluded in that way; most probably we have 

 to do here with a spontaneous development of acid of as yet 

 obscure nature. 



These few remarks do not pretend to be built on a very 

 strong basis. They only indicate a problem on the solution 

 of which I hope to be able to work more carefully in the future. 



18. IS THERE A LIPOLYTIC ENZYME IN THE 

 CORPUSCLES OF THE STARFISHES? 



In the chapter on the resorption in the urchins and the 

 cucumbers I shall mention the conceptions of Chapeaux 15) 

 as to the role of the corpuscles in the digestion and transpor- 

 tation of fats. In this chapter I only want to mention one of 

 his findings because I came to different results. 



Chapeaux studied the role which the corpuscles play in 

 the digestion of fatty substances. He found that fat-droplets 

 are taken up eagerly by the corpuscles and digested in the 

 cell-body. He finds a lipolytic enzyme present in them and 

 observes the development of acidity in plasmodia to which olive 

 oil has been added. This acid reaction was not found in a 

 control. 



In order to amplify my own experiments on the digestion 

 and utilisation of fatty substances in our group, I made some 

 experiments of my own on this question. 



A large quantity of starfish amibocytes was separated out 

 by means of a strong centrifuge; they were taken up in 100 

 c.c. of destilled water and a large quantity of neutral olive oil 

 and toluene were added. The whole was put into an incubator 



