344 



subservient lo, perhaps, biliary purposes. This view he has 

 advanced and supported in the article " Spleen^^'' in the Cyclo- 

 psedia of Anatomy and Physiology. 



To understand its bearings, it will be necessary to briefly refer 

 to the structure of the Spleen. 



The composition of this organ is very simple, being in general 

 terms, only a parenchyma, with septa-like digitations, which 

 form a support and framework for the ramification of a large 

 system of bloodvessels. In the higher vertebrates, however, 

 there are scattered through this parenchyma numerous closed 

 glands, which are filled with granular, chyle-like corpuscles ; 

 these are the so-called Malpighian bodies of the Spleen. They 

 are, I think, invariably wanting in the lower vertebrata. A vascu- 

 lar structure, capable of quite variable capacities, supported on a 

 framework of parenchyma, and sometimes a collection of closed 

 chyligenous glands, — these constitute the general structural fea- 

 tures of this organ. 



We will now proceed to notice the point at issue in K6lUker''s 

 theory. In the spleen-tissue of many animals, there are not un- 

 frequently noticed roundish or oval masses of a very variable 

 size, from ^-^^ to XbW ^^ ^^ i"ch in diameter. These appear 

 to be little sacs filled with blood-corpuscles in some stage of de- 

 composition. These bodies Kolliker thinks he has invariably 

 observed in all spleens, and he concludes that they are the worn- 

 out blood-corpuscles undergoing dissolution, and, therefore, that 

 these capsules are special, functional organs. 



Such an opinion, so unique, did not fail quickly to attract the 

 attention of physiologists, who examined its grounds of support. 

 In no instance that I am aware of have these views been substan- 

 tiated by subsequent observers, and some have gone so far as 

 even to deny that such blood-corpuscle-holding sacs existed. But 

 a discussion of these objections need not engage us here ; I wish 

 to record my own observations, which differ somewhat from them 

 all. During the past year I have examined the subject carefully, 

 and even before I was fully aware of the state of opinion among 

 the continental observers. My examinations of spleen-structure 

 have extended through the four classes of vertebrata, and in some 

 of these classes have been made on animals variously developed. 



