THE HARVEIAN ORATION. 737 



distended in the way of natural injection with chyle, as it is easy 

 enoug-h to see them distended in an animal, such as a rat, which 

 can be got to feed on fatty food, and can be killed at a proper 

 interval of time afterwards. He appears to have had very serious 

 as well as reasonable doubts as to the existence of any foramen in 

 the apices of these 'ampullulae' ; but the authority of Lieberkiihn, 

 whose 'Dissertatio Anatomica' (p. i8) he had himself edited, ap- 

 pears to have weighed with him more than his avToyj/Ca. Near, 

 therefore, as Sheldon came to seeing the whole truth, he just failed 

 of doing so entirely and completely ; and the views which Lieber- 

 kiihn had put forward (p. lo, loc. cit.) as to the great number 

 of the Peyerian glands in the lower segment of the small intestines, 

 being a proof that they held relation to secretion or excretion 

 rather than to absorption, prevailed and have prevailed, even into 

 our own day. These are Lieberkiihn's words : ' Quare ad finem ilei 

 plures quam in integro intestino positi erunt? Nonne propter 

 faeces jamjudum exsuccas et indurescentes ut lubricatae valvulam 

 facile transeant nee laedant?' In Henle's ordinarily and marvel- 

 lously excellent treatise on Anatomy, of date 1841, I find (p. 895) 

 the excretory character of the Peyerian follicles taken as something 

 certain ; the only thing left uncertain being the question as to 

 whether their contents found their way into the cavity of the in- 

 testine by a constantly patent, however small, duct, or by dehiscence, 

 as ova from an ovary. In 1850 the real meaning, the true physio- 

 logical import, of these glands was proved by Briicke. The method 

 of injection, of which I have spoken, enables us to demonstrate or 

 exhibit what was then proved, and that with the greatest ease. It 

 is difficult to understand how any one can now doubt that the 

 Peyerian glands are really but the pileorrhizae of the roots, the 

 glands the tubera, and the thoracic duct the trunk or stem of the 

 absorbent tree. 



If any apology be needed for my dwelling so long upon a point 

 of anatomy which has not merely much historical, but also much 

 practical, interest— the Peyerian glands being the part of the 

 organism especially affected by the poison of typhoid fever, which 

 I see has, amongst other aliases, that of 'Peyerian fever' (Walshe, 

 ' On Diseases of the Heart,' 3rd ed. p. 208)— I would add that I 

 was till recently under the impression that the actual demonstration, 

 the doing, of that which my Figure i, p. 734,. represents as done, 



