

CHAP. III.] CHARACTERS OF PANCREATIC JUICE. 199 



secretion ; and their results, while they extend, in the main corroborate 

 those of Heidenhain. In the quiescent pancreas of the rabbit, Fig. 13 A, 

 the cells are for the most part filled with granules, the transparent outer 

 zone being reduced to small dimensions ; the outlines of the individual 

 cells are very indistinct, with the margins of the alveoli smooth ; the 

 lumen of the alveolus is obscure ; and the blood supply is scanty. Upon 

 secretion being set up, Fig. 13 B, the margins of the active alveoli 

 become indented through a bulging of their constituent cells, the out- 

 lines of which now become distinct ; the granules retreat towards the 

 inner zone, bordering on the cavity of the alveolus, and as secretion 

 on, evidently diminish in number, the whole cell becoming hyaline 

 and transparent from the outer border inwards ; at the same time the 

 blood-vessels dilate largely, and the stream of blood through the capillaries 

 becomes full and rapid.' 



Quantity of Allusion has already been made to the difficulties which 

 pancreatic attend attempts to collect the whole of the pancreatic 

 juice secreted, juice secreted by an animal ; these difficulties explain 

 the discrepancies in the statements of various observers concerning 

 the amount of juice secreted either during a single act of digestion 

 or in a given time, as in 24 hours. As a result of observations on 

 temporary fistulaB, it has been estimated that, assuming the rate 

 of secretion in m'an to be in proportion to that in the dog. a man 

 would secrete in 24 hours from 211 'to 347 grammes 1 . The older 

 estimates founded on the observations of Ludwig and Weinmann 

 were much higher 2 . 



SECTION 3. THE PHYSICAL AND CHEMICAL CHARACTERS 

 OF THE PANCREATIC JUICE. 



In describing the general phenomena of the pancreatic secretion 

 some of its more prominent physical and chemical characters have 

 been referred to, though a complete description has been reserved for 

 this section. 



Physical Characters. 



The juice obtained from temporary fistulae or in permanent fistulse 

 when changes in the gland have not occurred, is. as has already been 

 said, a more or less viscid, gluey liquid. 



It contains suspended in it constantly certain morphological 

 elements (Kiihne 3 ). These are : colourless blood corpuscles of the 



1 Kiihne, ' Lehrbuch der physiologischen Chemie, 1866, p. 114. 



2 The reader is referred for data relating to the older experiments to Bonders, 

 Physiologic des Menschen, Vol. i. p. 263. 



3 Kiihne, 'Ueber das Secret des Pankreas,' Verhand. d. Naturhist. Med. Vereins zu 

 Heidelberg, Bd. i. Heft 4. 



