166 Mr John Goodsir on the Structure of the Intestinal 



interesting specimens into fresh spirits, I availed myself of the 

 opportunity of examining into the nature of the appearances 

 described and figured by Mr Cruikshank.* 



I removed one of the villi from Mr Cruikshank's prepara- 

 tion, t placed it between two glass plates, and had no diffi- 

 culty in recognising what had been described and figured by 

 the original owner of the preparation. With a low power the 

 extremity of the villus appeared bulbous and opaque. With 

 a higher power I observed that this opacity was due to the 

 existence, at the extremity of the villus, of a number of vesi- 

 cles of different sizes. The larger vesicles were pretty uni- 

 form in size, and about twenty in number. The smaller were 

 of different sizes and more numerous, and appeared gradually 

 to pass into the granular looking tissue of the attached extre- 

 mity of the villus. No blood-vessels could be detected, but 

 along the neck of the villus distinct traces of two or more opaque 

 lacteals were visible. The vesicles and the lacteals, when 

 viewed by transmitted light, were of a light brown colour ; but 

 when examined as opaque objects, against a dark ground, they 

 stood out of a dead white appearance, contrasting strongly 

 with the semi-transparency of the surrounding tissue. Re- 

 peated examinations of these preparations satisfied me that 

 Dr William Hunter and Mr Cruikshank were quite cor- 

 rect in describing and figuring radiating lacteals within the 

 villi, but that they were led into error in describing those 

 vessels as opening on the free surface of the gut, partly by 

 imperfect instruments and methods of observation, partly by 

 the general prejudice of the period in favour of absorbent 

 orifices. I also satisfied myself of what appeared highly pro- 

 bable from the commencement of the observations, that the 

 villi, when turgid with chyle, were destitute of their ordinary 

 epithelial covering. This circumstance I could not avoid con- 

 necting with the fact of the stomach throwing off its epithelia 

 during the process of digestion. I determined, therefore, to in- 

 vestigate the process of absorption of chyle in fresh subjects, 

 as the facts exhibited in Mr Cruikshank's preparations indi- 

 cated the probable existence of complicated processes going 

 on in villi during digestion. The analogy of the vesicular 

 bulbous extremity of the villus, to the spongiole of the vege- 



-* Loc Cit. Plate II, figs. 2, 3, t xiii. 4 N. 49, Bell Catalogue. 



