THE SPLEEN, AND SUPRA-RENAL CAPSULES. 563 



as the Malpighian bodies of the spleen, after the name of their discoverer; but since his 

 time, their existence has been denied, or other appearances have been mistaken for them. 

 According to Dr. E., they in all respects resemble the mesenteric or lymphatic glands in 

 miniature, consisting as they do of convoluted masses of blood-vessels and lymphatics, 

 united together by elastic tissue, so as to possess considerable firmness; and they further 

 correspond with them in this, that the lymph they contain, which was quite transparent 

 in their afferent lymphatics, now becomes somewhat milky, from containing a large 

 number of Lymph-globules. 



709. In regard to the functions of the Spleen, great uncertainty exists. 

 That the Spleen performs no action essential to life, has been repeatedly proved 

 by the experimental removal of it in many of the lower animals, and by the 

 accidental loss of it in Man, of which several cases are on record ; for after the 

 immediate effects of the wound were recovered from, the vital functions were 

 performed with no perceptible interruption, and health appeared to be com- 

 pletely restored. Hence the Spleen must be regarded as an organ of duplex 

 character, and probably of double function. The cellated structure may be 

 considered as a multilocular reservoir, capable of great distension, and lined 

 with a continuation of the inner membrane of the vein ; receiving blood on 

 the one hand, from the veins of the interior of the organ, and transmitting it 

 onward to the Vena Portae ; and on the other hand, acting as a reservoir for 

 the venous blood of the abdomen, when, from any cause, its passage into the 

 Vena Cava is obstructed. The splenic parenchyma, on the other hand, must 

 be regarded as a complex Lymphatic tissue, essentially resembling that of the 

 lymphatic glands, but differently arranged. In those animals in which it pre- 

 dominates, as in Man, the artery is large ; on the other hand, where the cellated 

 structure is most developed, as in the Herbivora, the Vein is very large, and 

 the artery comparatively small. Nothing completely analogous to a Spleen is 

 found in Invertebrated animals ; and from the absence of the Lymphatic 

 system in them, it is evident that the parenchymatous portion can have no 

 existence as such. Something analogous to the cellated portion of the Spleen, 

 however, exists in the venous system of many Cephalopoda ; and this circum- 

 stance is an additional proof of the duplicity of the character of this remarkable 

 organ. Out of the numberless theories of its operation, which have been at 

 different times brought forwards, the one which is most satisfactory to the 

 Author, and which corresponds best with the account just given of its cellated 

 structure, is that which regards it as a sort of diverticulum or reservoir ; 

 which may serve to relieve the Portal Venous system from undue distension, 

 under a great variety of circumstances. This system is well known to be 

 destitute of valves ; so that the Splenic vein has free communication with the 

 whole of it. Hence the Spleen will be a ready diverticulum for the venous 

 blood, when the secreting action of the Liver is feeble, so that the Portal cir- 

 culation receives a partial check ( 662), That any cause of congestion of the 

 Portal system peculiarly affects the Spleen, has been proved by experiment ; for 

 after the Portal Vein has been tied, the spleen of an animal, which previously 

 weighed only 2 oz., has been found to weigh a pound and a quarter, or ten 

 times as much. Now it is evident that congestion of the Portal system is liable 

 to occur when the alimentary canal is distended with food ; and this from two 

 causes, the pressure on the Intestinal veins, and the quantity of fluid absorbed 

 by these veins. Hence it may be conceived, that the Spleen, by affording a 

 reservoir into which the superfluous Venous blood may be directed, serves an. 

 important purpose in preventing congestion of other organs. From the obser- 

 vations of Mr. Dobson,* it appears that the Spleen has its maximum volume 

 at the time when the process of chymification is t at an end, namely, about 

 five hours after food is taken ; and that it is small and contains little blood 



* London Medical and Physical Journal, Oct. 1820. 



