41 



Vertebrates; in these lower animals there is a very strong 

 variation. As yet unpublished experiments of Dr. Morgulis 

 who was working in the same laboratory last summer, showed 

 that the blood picture of many invertebrates of various groups 

 is not constant at all, but shows a wide variation, due most 

 probably to the moment's feeding condition. 



Note. The perivisceral fluid of Strongylocentrotus and of 

 Toxopneustes is said by Mourson and Schlagdenhauffen 

 to be used in the Midi of France as a tonic. What might 

 account for such activity, I do not know. 



14. ARE THERE ENZYMES PRESENT IN THE 

 PERIVISCERAL FLUID? 



„Bei frischgefangenen, also in Verdauung begrifFenen Seeigeln 

 fand ich mehrmals in der Leibeshohle ein diastatisches, bei 

 Holothurien ein diastatisches und ein invertierendes Ferment". 

 (Cohnheim 17) p. 42). 



Bacterial action was excluded, because toluene was present; 

 no hydrolysis took place if the liquid was boiled. These experi- 

 ments according to Cohnheim, show the presence of enzymes 

 in a solution which except for some inorganic salts, does not 

 contain any other substances. „Dieser Refund ist chemisch recht 

 interessant, weil er das Vorhandensein von Fermenten in einer 

 Losung zeigt, die weder Eiweisz noch Kohlehydraten und 

 iiberhaupt organische Substanz nur in Spuren enthalt und so 

 einen Beweis mehr fiir die Nichteiweisznatur dieser Korper 

 liefert." He compares them to the „Fermentschlacken", found 

 more or less regularly in the blood and the urine of mammals. 



As a matter of fact, such result would be exceedingly inte- 

 resting, but I believe that Cohnheim in wrong in the inter- 

 pretation of his observations. I am more inclined to believe 

 that a small amount of corpuscles or remainders of corpuscles 

 present in the hquid may account for his result. 



In order to ascertain whether this could be the case I made 

 some experiments of my own on this question. 



Two large samples of perivisceral fluid of Thyone and Arbacia 

 were secured. One of each was centrifuged repeatedly with a 

 strong centrifuge in order to get rid of the corpuscles. This is 

 as a matter of fact, not as easy as one would suppose it to be. 

 One is almost never sure that no more corpuscles are present. 

 A part of the corpuscles seems to be crushed or ,,laked" which 

 is especially clear in Arbacia where the hquid is never colorless. 

 This is what made me think that an error of this kind might 

 have been made by Cohnheim. 



Cohnheim reports that he could observe this enzymatic 

 activity only in freshly caught specimens. For this reason I used 



