406 INTERNAL SECRETIONS OF PANCREAS AND SPLEEN. 



lobules supplied with islands. When secretory activity occurs, 

 the granules of the inner zone of the cells simply disappear in 

 the central lumen; but how and in virtue of what agency they 

 are transformed into secretion at this point has not been de- 

 termined. In the lobules supplied with islands of Langerhans 

 the effused serum more than satisfies this feature, since it sup- 

 plies two agencies thought to be capable of converting the 

 granules into trypsin; but what of the lobules deprived of 

 islands? How are their granules converted? 



To answer these questions we must first ascertain which 

 of the ferments credited to the pancreas can be shown to orig- 

 inate in the true acini. We have seen that, when the hilum 

 of the spleen is ligated and no splenic ferment can find its way 

 to the blood, the digestion of albumin ceases. It is, therefore, 

 evident that, in accordance with Herzen's view, the splenic 

 ferment is a sine qua non in the process through which tryp- 

 sinogen is converted into trypsin. But why does the oxidizing 

 substance not continue the conversion after ligation of the 

 splenic hilum? There is but one answer to this, viz.: zymogen 

 and trypsinogen are not similar bodies; while zymogen is converted 

 into some pancreatic ferment by oxygen, trypsinogen is not, and 

 always requires the splenic ferment. 



To illustrate this fact we submit, in extenso, two of Gachet 

 and Pachon's experiments, performed to show that it was the 

 spleen's ferment, and not its haemoglobin, that converted pro- 

 trypsin, which they term "preferment." Believing that zymo- 

 gen, which, as shown by Heidenhain, is very greedy for oxygen, 

 and "preferment" are the same bodies, their aim is to prove 

 that, injected in arterial blood, pancreatic ferments cannot be 

 converted into trypsin therein. But, interpreted from our 

 standpoint, since the blood contains oxidizing substance 

 which zymogen would readily take up, these experiments 

 prove that zymogen and their proferment (trypsinogen) differ, 

 as stated. 



"As the proferment of the pancreas becomes very easily 

 transformed into trypsin under the influence of oxygen," say 

 Gachet and Pachon, "it seems possible that splenic extracts, 

 intensely colored by the haemoglobin, should owe their tryp- 

 sinogenous power to the fixed oxygen of haemoglobin which 



