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



branches run directly across to the opposite side. It thus 

 occurs that in the centre of the follicles a non- vascular space 

 frequently remains, which, however, is not larger than such as 

 may be found between the capillaries in the periphery. One 

 or more of these communicating capillary branches also fre- 

 quently extend straight through the middle of the follicle * 



The veins originate in the superficial plexus, especially from 

 that situated at the base of the follicle, form short trunks 

 which pursue a tortuous course, and partly coalesce with the 

 veins of the villi, and partly open directly into a branch of the 

 venous plexus lying upon the muscularis mucosse. 



The bloodvessels ofPeyer's patches present a similar arrange- 

 ment to those of the follicles. The plexus lying subjacent to 

 them is characterised by its richness ; the larger trunks, both 

 arterial and venous, completely surround the margin of the 

 groups of follicles, and send numerous branches beneath the 

 follicles. The venous plexus is especially distinguished from 

 that of the other parts of the intestinal mucous membrane by 

 the circumstance that, besides the vertically descending veins 

 of the villi, numerous smaller and larger branches proceeding 

 from the follicles unite at more or less oblique angles to form 

 larger trunks, and thus cause a considerable alteration in the 

 otherwise characteristic appearance of this plexus. 



* For further information the reader is referred to F. Ernst, Ueber die 

 Anordnung der Blutgefasse in den Darmhauten, ll On the Arrangement of 

 the Vessels in the Walls of the Intestine." Zurich, 1851. His, in the 

 Zeitschrifi fur wissenschaftliche Zoologie, Band xi., p. 416. Frey, in idem, 

 Band xiii., p. 28. 



END OF VOL. 



Printed by Watson and Hazell, London and Aylesbury. 



