598 BLOODVESSELS OF THE ALIMENTARY CANAL, BY C. TOLDT. 



and transverse capillary branches of the villi varies con- 

 siderably in the intestines of different subjects, sometimes one 

 and sometimes the other preponderating. The arrangement of 

 the capillary plexus is also modified by the form of the villi. In 

 those that have a flat conical shape, as in the duodenum, the 

 transverse branches are usually smaller in number, whilst , in 

 cylindrical villi the longitudinally running vessels are less 

 developed, and the transverse branches are consequently more 

 numerous. In strongly contracted villi the capillary plexus 

 appears closer, and the vessels more tortuous. The plexus is 

 usually also more close near the apices of the villi. By the 

 union of several arches of capillary vessels the venous radicles 

 here originate, and, speedily coalescing, form a venous trunk of 

 considerable size, which descends vertically through the villus, 

 and joins with the veins of neighbouring villi. 



In their further course the veins thus formed descend through 

 the glandular layer without receiving any other branches or 

 forming anastomoses, and finally terminate by entering the 

 venous plexus lying subjacent to that layer. Where the villi 

 are absent, as in the large intestine, the transition of the ca- 

 pillary plexus into the veins occurs in a precisely similar 

 manner at the free margin of the folds which the mucous 

 membrane forms around the opening of the tubular glands. 

 The arrangement of the venous expansion beneath the Lieber- 

 kuhnian glandular layer differs essentially from the arterial. 

 Whilst the arteries break up in an arborescent manner into 

 fine meandering branches, the veins are formed from the 

 large venous trunks that descend from the villi. The venous 

 plexus of the intestine is distinguished from the analogous one 

 of the stomach by the more sharply defined limitation of the 

 territory belonging to the several venous trunks, and by the 

 more sparing occurrence of anastomoses. 



In the large intestine the arrangement of the bloodvessels is 

 similar to that of the stomach, with the exception that the 

 capillary system surrounding the glandular layer is not so 

 much ramified, so that in many parts only straight and but 

 little branched tubules are found between the glands from 

 which the close superficial venous plexus proceeds. The 

 trunks collecting the blood from these extend downwards 



