67 



Magensackes bei den Seesternen in erster Linie der Absonderung 

 des wirksamen Verdauungssaftes dienen, wahrend der riesige 

 Magen selbst lediglich als Behalter der aufgenommenen Nah- 

 rungskorper dient und nur insoweit eine active RoUe spielt, als 

 er sich vorstiilpend, die oft sehr groszen Beutetiere noch auszer- 

 halb des Korpers umschlieszt " 



Krukenberg, about whom we have given our opinion 

 already in the introduction, denies emphatically that food 

 ever penetrates into the „Lebergange" of the starfishes. He 

 fed fibrin stained with different dyes to these animals and the 

 result of his observations was, „dasz die sogenannten Radial- 

 anhange des Asteridenmagens reine Ausfiihrgange der Leberdriise 

 sind". In some cases he found parts of the water vascular 

 system colored even out to the tips of the arms, but no dye 

 present in the „liver". 



Similar observations were made by F r e n z e 1 and Fredericq 

 who also believed that the radial sacs only have secretory and 

 no resorbing activity or that they are the only secreting organ. 



Chapeaux, Hamann and C o h n h e i m have come to a 

 different conclusion. Chapeaux found that after the ingestion 

 of fat the cells of the radial sacs were all full of it. C o h n h e i m 

 proved by autodigestion-experiments that enzymes are present 

 just as well in the stomach as in the radial sacs. 



If the radial sacs are the exclusive or even the chief organ of 

 enzyme secretion, it must be possible to demonstrate a difference 

 in enzymatic activity between equal quantities of stomach and 

 radial sac material. On the contrary, if such difference is found 

 not to exist, if both prove to be about equally active, it is not 

 very probable, though yet concievable — on account of the 

 relatively enormous quantity of radial sac material present in 

 one animal — , that a difference can be shown. 



An equal quantity of stomach and of radial sac material was 

 secured. Equal quantities were taken rather than proportional 

 parts, because there is in reality about 7 or more times as much 

 radial sac as stomach material which would not give an unfair 

 comparison. Both were ground up with sand, to both an equal 

 quantity of gelatin, water, sodium carbonate — to keep the reaction 

 slightly alcahne — and toluene were added. The digests were 

 now placed in the incubator at 37° and kept there for 24 days. 

 After they had been taken out of the incubator the amount of 

 total non-protein nitrogen present in them was determined. 

 The proteins were precipitated with an excess of 5 "/o trichlor- 

 acetic acid. In an aliquot the amount of total nitrogen was 

 determined by means of the method of Folin. The diluted 

 digestion mixture was used and direct Nesslerisation. 



In both digests in which 11.5 gr. of tissue had been used, 

 almost exactly the same amount of nitrogen proved to be present. 

 In the digest of the lateral sacs. I found 144 mgr. of nitrogen, in the 



