bo 
to 
BULLETIN OF THE BUREAU OF FISHERIES. 
The conclusions to be drawn from the table are; 
(1) The pancreatic extracts may or may not show proteolytic activity. 
(2) The duodenum as a rule causes the inactive pancreatic extract to digest the 
gelatin and increases the digestive activity of an active pancreatic extract. 
(8) The greatest activation is produced by the spiral valve. 
(4) ‘The spleen occasionally activates the pancreatic extract. 
(5) The bile sometimes activates, sometimes has no effect whatever, and some- 
times slightly diminishes the digestive activity of the pancreatic extracts. 
(6) lextracts of the duodenum, spiral valve, and rectal gland haye no digestive 
webivily. 
(7) The bile alone has no digestive power. 
(8) Mxtracts of the rectal gland have no activating influence. 
(9) Extracts of the mucous membrane of the stomachie sac and pylorie tube 
have no activating action, 
Amylopsin and lipase. Krukenberg (1877), Richet (1878), and Yung (1899) 
found amylopsin and lipase in the pancreas of European elasmobranchs. To deter- 
mine the presence of these enzymes in the pancreas of the American elasmobranchs 
experiments were made (1) on the amylolytic activity and (2) on the lipolytic activity. 
|. Water-glycerin extracts of the pancreas, slightly acidified with acetic acid, 
were made at different times from different lots of fishes. To 5 ¢. ¢ of a starch 
paste, free from sugar, was added 5 ¢. ¢. of the extract. After a short period 
the mixture was examined for sugar by Kehling’s test. If negative, the tests were 
repeated at hourly intervals for six hours. In every case control tests were made, 
The results of the experiments are as follows: 
Dinstatie enzyme 
(amylopsin), 
Species, 
Number | ,, in 
of tests. | I onl tive 5 
as | } “ 
; | 
Carcharthai{toral is iss. ss scbw scisie'vs «inuierss sic vib cne'exclsiesensilgaiesip aa alee we ices’ eerids ene tineeteatstee Pre Tenia 6 4 
Crreharhinus obseurus . 2 2 
Limna cornublen .... 2 0 
Mustelus canis ....... Sele pinepnie cates aoa iT 6 
Sqiialus acanthiag...... Shee - ore 2 1 
Raja erinacen .......... 10 0 
Tetronaree occidentalis. . ale oda ad ae | 1 
Dasyatis centrura ........ , eas i 1 
The table shows that the pancreas of elasmobranchs may secrete the diastatic 
enzyme or its zymogen. ven in the case where the tests were negative I should 
expect on further investigation to find that the pancreatic extracts have the power to 
convert stareh to sugars. 
2. To determine the presence of the lipolytic ferment of the pancreas, the 
fresh pancreas of Mustelus canis, Carcharias lttoralis, and Raja erinacea, the only 
elasmobranchs available at the time, was used. The methods employed and the 
results obtained are as follows: 
(a) The fresh pancreas of the three fish mentioned was cut finely and mixed sepa- 
rately with a little water to make a thin paste. To a small quantity an equal volume 
of olive oil and litmus solution was added, and this mixture was kept at 80° C. fou 
