114? THE FUNCTION 



form d ; the intestines, no less than the stomach, are indebted to 

 it for their tenacity and strength. 



" The interior, lined by its delicate epithelium, and deserving 

 the name of villous in the small intestines more than in any other 

 part of the canal, forms, in conjunction with the inner surface of 

 the former coat, here and there, undulated ridges and rugous 

 plicae, which, in dried and inflated intestines, resemble the blade 

 of a scythe, and are termed the valvulae conniventes or Kerk- 

 ringhianae. 6 



" The villi, which are innumerable f upon the inner surface of 

 the intestines, and whose beautiful and minute vascular structure 

 was first carefully investigated, though described with exagger- 

 ation, by LieberkiihnS, may be, perhaps, compared, while desti- 

 tute of chyle, to little loose pendulous bags, internally soft and 

 spungy ; but, when distended with chyle, they have the appear- 

 ance of a morel. 



" The base of these villi is surrounded by innumerable glan- 

 dular follicles, adhering chiefly to the nervous coat, and opening 

 into the intestinal canal by a very small orifice, through which 

 they discharge the mucus that lines the whole track of the in- 

 testines. 



" These are distinguished into three orders. The Brunnerian, 

 largest, solitary, found in most abundance in that part of the 

 duodenum which is contiguous to the pylorus. 11 The Peyerian, 

 smaller, aggregated, found chiefly at the termination of the small 

 intestines, about the valve of the colon. * Lastly, the Lieber- 

 -floF *m6 oiiJ : vm'til ^o 37a?vio r--?r* V 1 *T3;s'v> -r^nr-ir: ad'! 



d " B. S. Albinus, Dissert, de arteriis et venis intestin. hominis, with coloured 

 plates. LB. 1736. 4to. 



Also his Annotat. Acad. L. iii. tab. i. ii." 



e " Kerkring, Spicilegium anatomicum, tab. xiv. fig. 1, 2." 



f " He estimated their number, in the small intestines of an adult, to be about 

 500,000." 



8 " Defabrica et actions vulorum intestinor. tenuium hominis. LB. 1745. 4to. 



J. Bleuland, Descriptio vasculorum in intestinorum tenuium tunicis. Ultraj. 

 1797. 4to. 



R. A. Hedwig, Disquisitio ampullarum Lieburkiihnii. Lips. 1797. 4to. 



C. A. Rudolphi, Anatomisch-physiologische Abhandlungen. Berlin. 1802. 8vo. 

 p. 39." 



h " J. Conr. a Brunn, Glanduke duodeni s. pancreas secundarium. Francof. 

 1715. 4to. fig. 1." 



1 J. Conr. Peyer, De Glandittis intestinorum. Scafhus. 1677. 8vo. especially 

 fig. 3." 



