288 ABSORPTION AND SANGUIFICATION. 



food, and a great afflux of arterial blood takes place to the mucous 

 membrane, the veins of the portal system will be liable to increased 

 pressure from without, whilst their contents will be augmented by the 

 quantity of fluid newly absorbed from the alimentary canal. In this, 

 as in the preceding cases, the distensibility of the spleen makes it a 

 kind of safety-valve, by which undue distension of the portal system is 

 relieved. It has been ascertained that its maximum volume is attained 

 about five hours after a meal, when the process of chymification is at an 

 end, and that of absorption is taking place with activity ; and the in- 

 crease is proportional rather to the amount of the fluids ingested, than 

 to that of the solids. Although the Human Spleen has no true cavern- 

 ous structure, yet its veins are obviously very distensible, so that a great 

 accumulation of blood may take place in it. Thus, in Asphyxia, when 

 the circulation of blood is checked in the Lungs, and when the stagna- 

 tion extends itself backwards to the right side of the heart, the vena 

 cava, and thence to the portal system, the Spleen is often found after 

 death to be enormously distended with blood. And in the cold stage 

 of intermittent fever, in which a great quantity of blood is driven from 

 the surface towards the internal organs, the Spleen receives a large 

 portion of it, so that its increased size becomes quite perceptible; and 

 in cases of confirmed Ague, the Spleen becomes permanently enlarged, 

 forming what is popularly known as the "ague-cake." 



508. But besides this safety-valve function, there can be little ques- 

 tion that the Spleen performs some other, which is related more closely 

 to the nutritive operations, and which in some degree correspond with 

 that performed by the Absorbent glandulse. The multitude of glandu- 

 lar cells in immediate relation with blood-vessels, and the appearances 

 of rapid development and degeneration which these present, taken in 

 connexion with the fact that there is no other outlet for the products of 

 their action than that which is afforded by the veins, clearly indicate 

 that whatever this product may be, it is destined to form part of the 

 blood ; and that the Spleen is, therefore, an organ of sanguification. 

 This view is confirmed by the remarkable fact, ascertained by recent 

 experiments, that after the spleen has been extirpated, the lymphatic 

 glands of the neighbourhood increase in size, and cluster together as 

 they enlarge, so as to form an organ which at least equals the original 

 spleen in volume. This circumstance explains the reason for the almost 

 invariable negative result of the extirpation of the spleen ; for although 

 the operation has been frequently practised, "with the view of deter- 

 mining the functions of the organ by the symptoms presented by the 

 animals after its removal, no decided change in the ordinary course of 

 their vital phenomena has ever been observed, and the health, if at all 

 disturbed for a time, is afterwards completely regained. Now if the 

 principal function of the Spleen be the same with that of the lymphatic 

 glands in general, it is easy to understand how its loss may be at once 

 compensated by an increased action on their part, and how it may be 

 permanently replaced by an increased development of certain of those 

 bodies. It is worthy of remark, that a Spleen is found in all Verte- 

 brated animals which have a distinct Absorbent system ; but that no 

 organ exactly corresponding with it exists in the Invertebrata, which 



