PANCREATIC FLUID. 169 



arc due, as Bernard has suggested, to the circumstance that when the opera- 

 tion for the formation of a pancreatic fistula has been attended with much 

 violence, when the gland has become inflamed, and the health of the animal 

 has in consequence suffered, the fluid secreted is abnormal, and differs both 

 in quantity and in many of its most essential properties, from the healthy 

 secretion. From these considerations, and from the probably intermittent 

 character of the secretory act, it is manifest that only an approximate esti- 

 mate of the absolute quantity can be made. Bernard estimates the quantity 

 secreted per hour in the duo-, for every 1 lb. weight of the animal, at about 

 15 grains ; Schmidt and Kroger at from 20 to 35 grains j 1 Skrebitzky and 

 Bidder at from 21 to 35 grains. If this last estimate were applied to man, 

 it would give from 12 ozs. to 16 ozs. av. as the total quantity of pancreatic 

 juice secreted per diem. Bernard describes the gland as pale and flaccid 

 during the period of fasting, and as rosy, but not deep red, some time after 

 food has been taken, when the secretion is rapidly poured forth. The activ- 

 ity of the gland seems to be greatest at the middle or towards the close of 

 gastric digestion,' 2 and at the period, therefore, of the passage of the con- 

 tents of the stomach into the small intestine. Corvisart attributes the secre- 

 tion to a kind of charging of the pancreas with albuminous compounds 

 absorbed during gastric digestion, for on the introduction of food, or of the 

 products of gastric digestion below the entrance of the pancreatic duct, no 

 increase in the flow of the secretion occurred. [Bernstein has shown that 

 with the entrance of food into the stomach the pancreatic secretion rapidly 

 increases, and soon reaches its maximum ; then slowly decreases, and towards 

 the sixth hour again increases. Heidenhain, in a long paper, has put forth 

 the following: During the state of hunger the granular interior portion 

 of the pancreatic cell occupies a larger part, whilst the homogeneous exterior 

 of the cell occupies a smaller part; that during the first period of digestion, 

 when the most active secretion takes place, there is a lessening of the size of 

 the whole cell through a using up of the granular interior. Whilst new 

 materials are added to the exterior of the cell, this portion of the cell is 

 increased in size; that during the second period of digestion, when the secre- 

 tion sinks and stops, there is a renewal of the granular interior of the cell at 

 the expense of the homogeneous exterior, extreme diminution of the latter, 

 and increase of the'sizeof the whole cell; that, during long fasting, there is a 

 gradual increase of the external portion of the cell to its original size, 

 with a small decrease of the interior granular portion; the cells during their 

 physiological activity use up their granular interior, whilst there is an 

 addition of new material; in other words, there is a metamorphosis of the 

 granular matter into secretory elements with the increase of nutritive materials 

 in the formation of the homogeneous part of the cell, which, in its turn, is 

 converted into the interior granular material. The general shape of the cell 

 depends on the relative rapidity with which these processes are accomplished. 



1 See M. Edwards, Lee. sur la Physiol., 18GO, p. 522. Colin obtained about 10 

 oz. per hour from a, cow of medium size and from a horse, but only 3 drachms from 

 a pig. 



* Wcinmann observed in a dog during the first hour after a full meal 1510 grains 

 secreted, whilst after a 45 hours' fast only 7i grains (Henle and Pfuuffer's Zeitschrift, 

 N. F., Band iii, p. '247). Kroger obtained 384 grains during the first hour, 271. in 

 the 2cl, 225 in the 3d, 4th, 5th, and 6th ; 176 in the 7th, 8th, and 9th ; 165 from the 

 10th to the 14th ; and 103 from the 19th to the 24th (Arehiv. Ge'n. de Mod., i, 1861, 

 p. 533). Bernstein (Leipziger Arbeiten, 1870, p. 6) obtained scarcely any from fast- 

 ing dogs, but remarked a considerable increase (0.6 2 2 c.c. in 10 uiin.) during the 

 first hour after feeding, the quantity attaining its maximum at the 2d and 3d"honr 

 (about 5 c.c. in 10 min.). then diminishing to the 5th hour, when a slight increase 

 took place till the 7th hour, after which it gradually fell to zero. 



12 



