324 



STOMACH AND INTESTINE. 



rapid endosmose of water. But they are very 

 quickly dissolved or burst, by contact with 

 most of the fluids which are generally used 

 in preparing such specimens for microscopic 

 examination. 



During the five years that I have made the 

 stomach an object of frequent (though inter- 

 rupted) research, I have examined numerous 

 specimens from the perfectly fresh stomachs 

 of about thirty species of Vertebrata. The 

 following is an outline of the few results I 

 have obtained. As regards the pyloric tubes, 

 those of the Cat, Rabbit, Hog, Ox, and 

 Guinea-pig, resemble those of the Dog, in 

 containing a columnar epithelium, and having 

 a distinct calibre to their termination. Those 

 of the Horse resemble the tubes of the human 

 stomach in possessing the oval or gastric cells. 

 In most, if not all of these animals, the tubes 

 ramify. As respects the cardiac tubes, the 

 minute central calibre observed by Koelliker 

 in those of the Dog appears to be also present 

 in the Cat and Guinea-pig ; and, from analogy, 

 is not unlikely to exist in most Vertebrata. 

 The large oval cells are the rule throughout 

 the Vertebrate kingdom. And in many Rep- 

 tiles, as well as in the very young animals of 

 most orders, the numerous cytoblasts enclosed 

 by these cells are much more distinct. In 

 only two instances have I found no large 

 cells present in the cardiac tubes, and in both 

 of these, the stomach was evidently disorgan- 

 ized by commencing putrefaction. In some 

 Fishes, however such as the Mackerel it 

 is only the middle or apex of the F-shaped 

 stomach which is occupied by tubes. And 

 in the Minnow, Carp, and Tench of the 

 Cyprinoid genus, as well as in the river Lam- 

 prey (Pelromyzon fluviatile) no tubes are 

 present. Finally, while there are many species 

 in which the gastric structures appear to be 

 softer and more delicate during the time of 

 digestion than in the fasting state, in none 

 have I been able to verify the least difference 

 in the morphology of the organ at these two 

 periods. 



Those who are familiar with the diffi- 

 culties that oppose the successful examina- 

 tion of the softer tissues of the animal body 

 will probably bear with me if I end this de- 

 scription by what may seem a superfluous 

 caution to the observer. There are many 

 appearances seen in these delicate tubes, which 

 are produced by the mechanical violence 

 necessary to their isolation, aided by the 

 softening of incipient putrefaction or self- 

 digestion, or by the endosmose of the di- 

 lute fluids which are sometimes added to 

 such specimens in preparing them for the 

 microscope. Thus the tubes often deviate 

 from the above account in the absence of 

 gastric cells, in the presence of short branches 

 that are given off near their blind extre- 

 mities, and in the spiral or bulbous shape 

 which these ends sometimes assume. Indeed, 

 when we reflect upon the extreme tenuity of 

 their basement membrane, the nature of their 

 contents, and the firmness with which they 

 are imbedded in a dense areolar and muscular 



tissue, we shall scarcely be surprised to find, 

 that the violent disruption of these attach- 

 ments can distort the tubes, or break up their 

 soft contents. But the careful manipulation of 

 perfectly fresh specimens, in a proper fluid me- 

 dium (such as the serum of the blood, or a 

 strong solution of common salt) renders these 

 appearances so rare, as to render it highly 

 probable that they are accidental. While 

 conversely, the application of a slight pres- 

 sure, the use of water and dilute acids, and 

 the commencement of digestive or putrefactive 

 softening, will often produce them in a spe- 

 cimen from which they were formerly absent. 



In addition to the cylindrical tubes, some * 

 anatomists have found in the stomach ramified 

 glands, which end in acini or dilated extre- 

 mities. These are stated to occupy the 

 neighbourhood of the pylorus, wherethey form 

 a kind of transitional structure between the 

 gastric and the duodenal glands. I have once 

 or twice seen appearances in the tubes of this 

 part which corresponded pretty closely with 

 the above description. In two other instances, 

 a single flask-shaped dilatation was appended 

 to some of the ordinary tubes, which it thus 

 doubled in diameter. But the arrangement of 

 these latter dilatations, as well as the condition 

 of the remainder of the specimens, left me little 

 doubt that they were due to accidental 

 violence, which had distended the terminal 

 branches of a tube with a large portion of its 

 displaced contents. While their shape and 

 situation (in the mucous membrane itself, 

 instead of its submucous tissue) sufficed to 

 show that they were not lenticular glands ; 

 an argument which will equally militate 

 against the notion of their being a transition 

 to the duodenal glands, since these occupy a 

 similar position. 



Lenticular glands are also found in the 

 stomach. As regards their shape, size, 

 situation, and contents, they correspond so 

 completely with the solitary glands of the 

 intestine, that we may refer the reader to 

 these for their special description. Their 

 number varies extremely. Sometimes it is im- 

 possible to find any. In other specimens, they 

 are scattered more or less thickly through- 

 out the whole organ. They are said chiefly 

 to affect the lesser curvature ; but I have seen 

 them sown very plentifully over the pyloric 

 region only. In children* they are rarely 

 absent. And among the brute Mammalia, 

 they are found occasionally in the Dog f, and 

 constantly in the Pig. % Structures more or 

 less analogous to these glands probably also 

 exist in the Beaver, Kangaroo, Dugong, and 

 many other animals. 



Matrix. The cylindrical tubes of the sto- 

 mach are united to" each other, in their whole 

 length, by a sparing quantity of a fibrous 



* Bruch (in Henle and Pfeufer's Zeitschrift. f. 

 Rat. Path. Bd. viii. p. 272. et seq.) ; Ecker (id. op. 

 1852. p. 244.). Compare Bischoff (in Mueller's Ar- 

 chiv. 1838. p. 503.) 



f Bischoff, Op. cit. p. 510. 



j Id. op. ; also Wasmann (DeDigestione Nonmilla. 

 Berlin. 1839. p. 8.), and Koelliker, Op. cit. p. 150. 



