116 THE FUNCTION 



Albumen and albuminous substances, which are the source of 

 the chyle and so abundant in the duodenum and jejunum, gra- 

 dually disappear, so that a great part of the chyle is generally 

 formed and absorbed before the digested mass reaches the ileum.<i 

 The contents become of a brownish yellow colour, and of a dis- 

 gusting odour. 



" After becoming more and more inspissated in their long 

 course through the ileum, they have to overcome the valve of 

 the colon and pass into the large intestines. To facilitate this, 

 the extremity of the ileum is lubricated very abundantly by 

 mucus. 



" The valve of the colon 1 ', or, as it may deservedly be termed 

 after its discoverer, the valve of Fallopius 8 , is a short process or 

 continuation of the portion of the ileum that penetrates into 

 and is surrounded by the cavity of the large intestine. Its 

 external lips, while a neighbouring fold of the large intestine at 

 the same time projects considerably, are composed 1 , not like 

 other similar folds, merely of the interior and nervous coats, but 



q Dr. Prout, Thomson's Annals of Philosophy. 1819. 



r " Haller, Devalvula coli. Getting. 1742. 4to., reprinted in his Oper. minor. 

 t. i. p. 580. sq. 



T. Mich. Rbderer, De valvula coli. Argent. 1768. 4to." 



s " The various opinions respecting the discoverer of this remarkable valve are 

 well known. Haller's Elementa, t. vii. P. I. p. 142., may be consulted on this 

 point. 



In the mean time I am certain that, long before the period at which its disco- 

 very is in general dated, it was accurately known to that immortal anatomist 

 Gabr. Fallopius. In the library of our university there is a manuscript of Fal- 

 lopius, containing, among other things, his anatomy of the monkey, in which is an 

 account of the structure and use of the valve of the colon, delivered in a public 

 demonstration at Padua, Feb. 2. 1553, in the following words ; ' The use of the 

 ctecum in the monkey is to prevent the regurgitation of the food during progression 

 on all fours- This is proved by the circumstance of water or air t thrown into the 

 rectum, reaching the ccecum, but not passing beyond the large intestines. But, if 

 impelled from above, it passes into them. The reason is this, at the insertion of 

 the ileum are two folds, which are compressed by inflation and repletion, as occurs 

 in the heart, and prevent retrogression; wherefore, in man, clysters cannot pass 

 and be rejected through the mouth, unless in a weak and diseased state of the intes- 

 tines.' " 



c " A view of a recent and entire valve is exhibited by B. S. Albinus in his 

 Annotal. Acad. L. iii. tab. v. fig. 1. 



And overcharged by inflation and drying, in Santorini's Posthumous Tables, 

 xiv. fig. 1,2." 



