53 



at 37° and at certain intervals titrations were made on 20 c.c. 

 samples. On 20 c.c. of the original liquid a control titration 

 was made. 



The results of this series of titrations are given in table 10. 



Table 10. 

 Titrable acidity of a digest of olive oil and corpuscles. 



These figures indicate very clearly that if there is any in- 

 crease in acidity, which does not fall within the limits of 

 error, that this increase is too slight to have any biological 

 meaning. A priori it is not improbable that in these amibocytes 

 which are primitive and independent cells without any special 

 function, a hpase should be found, just as well as in an Amoeba. 

 More important, however, is the question, whether this enzyme 

 plays a role in the digestive processes of the animal as a whole. 

 This seems to be very improbable, considering our figures. 



I have also tried to study the same problem in two other 

 ways. Two fairly large quantities of coelomic fluid of Arbacia 

 were secured. One was centrifuged in order to remove the 

 corpuscles, the other one was left as it was. To both an equal 

 quantity of . olive oil was added and some toluene. Then 

 they were placed for two days in an incubator at 37° After 

 that time both gave exactly the same color with a piece of 

 litmus paper, only to neutral litmus paper they showed a very, 

 very slight acidity. If there was any difference at all, it was 

 too slight to be worthwhile mentioning. 



After this I repeated the experiment in a way similar to 

 that which Chapeaux employed. A large quantity of amibo- 

 cytes, collected by means of a centrifuge, was put into a deep- 

 depression slide, a drop of olive oil was added, the whole 

 covered with a cover-glass and put into the incubator. A very 

 distinctly acid reaction was found after 24 hours. After my 

 previous results I was rather surprised to find this and therefore 

 I decided to run a control without olive oil. The same acid 

 reaction appeared after a short time. Most probably the de- 

 caying material had produced an acid of some kind, which had 

 escaped my attention in the titration experiment on account of 

 its great dilution or which did not appear there on account 

 of the presence of toluene. If toluene was added to the samples, 



