338 



STOMACH AND INTESTINE. 



The anatomy of the fresh stomach also 

 suggests other conjectures, which confirm 

 the conclusion which we have deduced 

 from the above sources. We have already 

 noticed that, in the Dog, the columnar epi- 

 thelium forms but a single row, and that it 

 covers all the ridges during the digestive act. 

 Hence the columnar cells can scarcely be 

 stripped off in successive layers at this time. 

 While the close attachment of each of these 

 cells to those around it, together with their 

 uniform appearance in situ, renders it alike im- 

 probable, either that a cell is extruded singly 

 and then bursts, or that each, as it fills, rup- 

 tures and collapses. All those within a tole- 

 rably wide circuit of membrane seem absolutely 

 similar and coeval. 



In some cases, however, the gastric juice 

 does contain columnar epithelia mingled with 

 the food. In the Dog, this appearance is un- 

 usual, and the number of such shed cells is 

 small. In the Rabbit, their separation is more 

 frequent and extensive. While in the Pig, it 

 often forms a more or less continuous layer, 

 which is almost moulded to the ridges of the 

 stomach and the mouths of its tubes*, and 

 leaves the mucous membrane below denuded 

 of this its proper covering. But it remains for 

 future researches to show, whether this ap- 

 pearance is due to mechanical violence; to 

 commencing putrefaction; or to the distur- 

 bances implied in the muscular contraction, 

 the exsudation, and the other incidents of 

 the act of death. 



And whatever the interest attaching to 

 such a dehiscence of these columnar cells, 

 it can scarcely have any but a very indi- 

 rect relation to the healthy secretory pro- 

 cess that obtains in the living man or clog, 

 in whom the pure gastric juice is completely 

 structureless. This fact, announced by Beau- 

 mont, at a period when microscopy was much 

 less understood than at present, has since 

 been repeatedly confirmed in observations on 

 gastric fistulae which have been instituted 

 by Blondlot, Bidder, Schmidt, Huebennet, 

 and myself. And if great care be taken not 

 to disturb the surface of the mucous membrane, 

 we may often verify it in the fresh stomachs 

 of dogs which have been killed immediately 

 after feeding. 



Here again we may refer to Dr. Beau- 

 mont's numerous observations.-f- He made 

 use of magnifying glasses, by the aid of which 

 he could distinguish the spheroidal glandular 

 follicles, and the papillae situated in their in- 

 terstices. These papillae, or villi, he found to 

 be scarcely visible until food was applied to 

 the mucous membrane ; when they underwent 

 a kind of erection, and protruded from its 

 surface in the shape of small sharp processes. 

 From these, according to this faithful observer, 

 the gastric juice appears to exsude. Its secre- 

 tion begins by the gradual appearance of innu- 

 merable lucid specks, which are smaller than 

 the mucous follicles. These specks or points 



* Compare Koolliker, p. 150. 



t O/A rit. pp. 95, 96, 128. et passim. 



rise through the transparent mucous coat: 

 and seeming to burst, discharge themselves 

 upon the very points of these vascular papillae, 

 as a thin, transparent, colourless, limpid, acid 

 fluid ; which collects in small drops, and 

 spreads over the whole gastric surface. 



So thoroughly persuaded was Dr. Beaumont 

 that the fluid exsuded from the papillae alone, 

 that he had not the least doubt the excretory 

 ducts of the follicles were enclosed in these 

 villi, and terminated in the lucid specks just 

 alluded to ; although he admits that he could 

 not see any apertures here. 



Comparing this description with what we 

 now know respecting the anatomy of the mu- 

 cous membrane, it is difficult to avoid coming 

 to the conclusion, that the large and nume- 

 rous capillaries beneath its ridges are in 

 some way intimately connected with the 

 secretion of the gastric juice. And whether 

 this conjecture be right or wrong, the charac- 

 ters of this secretion corroborate the con- 

 clusion already deduced from the anatomy 

 of the dead stomach : viz. that the gas- 

 tric juice is not composed of a shed epi- 

 thelium. In like manner, the rapidity with 

 which it exsudes seems to contradict any 

 theory of even the most rapid solution of 

 columnar* cells. And since anatomy shows 

 that, until the end of gastric digestion, these 

 cells, if dissolved, are immediately replaced by 

 others, it follows, that to assume such a 

 process of dehiscence would imply a rapidity 

 of growth and organization, such as has never 

 yet been verified in the higher Vertebrate 

 animals. 



The latter quantitative objection may be bet- 

 ter carried out in detail. In Schmidt's expe- 

 riments, a dog secreted ^jth of its weight of 

 comparatively pure gastric juice in one hour. 

 Transferring such an estimate to an average 

 man of 140lbs. weight, it would follow that the 

 human stomach, the whole mucous membrane 

 of which scarcely weighs 4oz., can com- 

 pletely reconstruct its entire cell growth, 

 which is, at most, only half of this weight, 

 about sixty times in a single hour ! 



As regards the source of the acid, the 

 above statementby Dr. Beaumont is supported 

 by an interesting obervation of Bernard f ; 

 who finds that it is only the surface of the 

 mucous membrane which exhibits an acid 

 reaction, either in the digesting or fasting 

 state. This statement I can confirm : al- 



* When freed from their attachment, these co- 

 lumnar cells often undergo what seems to be a 

 rapid solution in the surrounding fluid under the 

 microscope. The first stage of this exhibits them as 

 v<rry delicate husks, which appear to have emptied 

 themselves after losing the lid of cell-wall at their 

 larger extremities. Their sides now often collapse : 

 and increasing transparency soon renders them invi- 

 sible. This process'occurs so quickly as to resemble 

 a digestive solution. But it is difficult to determine 

 how far it is effected by the contents of the cell 

 itself, apart from the surrounding fluid. A layer 

 of mucus generally occupies the neighbourhood of 

 any cut surface of gastric mucous membrane, and ap- 

 pears also to consist of the dissolved contents of cells* 



t Gazette M<<dicale, Mars 16. 1844. 



