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



Inasmuch as this plexus is exclusively composed of tubes of 

 larger calibre, and is also exclusively fed by the above-described 

 veins, it can be distinguished with remarkable facility when 

 seen from the surface, as in fig. 116, from the arborescent 

 terminal expansion of the arteries. From this venous plexus 

 larger vessels take origin, which perforate the muscularis 

 mucosse, join the arteries, and, accompanied by them, traverse 

 the submucous tissue, where they unite with others to form 

 strong vessels that perforate the muscular tunic of the stomach. 



Mucous MEMBRANE OF THE INTESTINE. 



With the exception of the large intestine, the arrangement 

 of the bloodvessels of the mucous membrane throughout the 

 whole extent of the alimentary canal is essentially similar, 

 being modified only by the number and size of the villi, the 

 distribution of the glandular follicles, Peyer's patches, etc. 

 The arteries reaching the intestine between the layers of the 

 mesentery perforate its muscular coat with the accompanying 

 veins, and run in the submucous tissue chiefly at right angles 

 to the axis of the tube. They communicate with each other 

 by_longitudinal and oblique branches, and form a wide-meshed 

 plexus. The venous trunks accompanying them likewise form 

 a plexus, which may be distinguished from that of the arteries 

 by the more frequent anastomoses and the larger size of the 

 vessels. If the intestine of the mature foetus of the rabbit after 

 injection be divided along the attachment of the mesentery, 

 and the flat surface examined, this vascular network appears 

 in the form of extremely delicate arcades, which, commencing 

 at the attachment of the mesentery, extend on either side about 

 one-third round the whole circumference of the intestine. Be- 

 yond this point the arteries and veins pursue a separate course. 



The numerous branches proceeding from the submucous 

 arterial expansion divide, after they have traversed the mus- 

 cularis mucosse, and have reached the glandular layer of the 

 Lieberkiihnian follicles, into capillary arches, which coil 

 spirally around the glandular tubes, are about 0*007 of a milli- 

 meter broad, and extend to the surface of the mucous mem- 

 brane, whence branches pass off to the villi. Other arterial 



