510 



SPECIAL HISTOLOGY. 



Fig. 205. 



The bloodvessels of the gastric mucous membrane are very numerous, 

 and their distribution is quite characteristic (compare Fig. 205, repre- 

 senting the vessels of the large intestine, whose 

 arrangement is almost the same). The arteries 

 begin to divide in the submucous connective tis- 

 sue, in such manner, that only their finer branches 

 reach the mucous membrane, in which, gradually 

 breaking up into capillaries, they ascend in great 

 numbers, perpendicularly, between the glands and 

 form a network of fine capillaries of 0-002-0-003 

 of a line, around the tubes, which extends as far 

 as to the apertures of the glands. Here this 

 network, which we may regard as continuous 

 through the whole stomach, passes into a super- 

 ficial reticulation of somewhat larger capillaries, 

 of 0-004-0-008 of a line, whose meshes, in man, 

 are polygonal, 0-02-0-04 of a line in diameter, 

 and encircle the apertures of the glands ; it is 

 more complicated or more simple, according to the breadth of the in- 

 terspaces of the glands and the occurrence of elevations upon them, but 

 seems never to consist of simple vascular rings. From this network the 

 veins, which are relatively wide, arise by many radicles ; they then, fur- 

 ther apart from one another than the arteries, and receiving no more 

 blood, penetrate the glandular layer, and upon the outer surface of the 

 mucous membrane, enter, often at right angles, a wide venous network 

 with partly horizontal vessels, in the submucous tissue. 



The lymphatics of the stomach form a superficial fine network and 

 a deep, coarse, one ; and can only be demonstrated by injection. The 

 numerous small branches which pass from the mucous membrane, their 

 aggregation into larger trunks, and final penetration of the muscular 

 tunic, are readily seen in large Mammalia, killed during digestion. The 



FIG. 205. Vftssels of the large intestine of a Dog, the raucous membrane being cut 

 through perpendicularly ; a, artery ; 6, capillary network of the surface, with glandular 

 apertures ; c, vein ; d, capillary network round the glandular tubules in the thickness of the 

 mucous membrane. 



they occasionally exist in the dog, invariably in the pig, and so far as the latter animal is 

 concerned, I can, w^ih Wasmann, confirm this statement. They are here, as Bischoff sup- 

 poses and as is evident from Wasmann's description, not isolated, but aggregated glands, true 

 minute Peyer's glands. The aggregations measure l-2 lines, are distributed especially upon 

 the cardiaand small curvature, and are readily seen upon stripping off the muscular and sub- 

 mucous tissue. At first sight, they appear to lie entirely in the last-named layer, but if the 

 attempt be made to detach them, it is found that this cannot be done without tearing the 

 mucous membrane, to which they closely adhere. On the internal surface, small depres- 

 sions are seen where these patches occur, and the gastric glands are here either absent or 

 undeveloped." Kolliker. Mikr. Anat. II. 2, p. 151. TRS.] 



