796 



SPLEEN. 



spleen to the whole body is, in an embryo of 

 ten weeks old, as 1 to 3000 ; in the eighth 

 month it is, according to Huschke, as 1 to 

 720 ; while at birth, he states it to be as 1 to 

 357 ; in the adult as 1 to 235 to 400 ; and in 

 old age as 1 to 600 to 800. From these data 

 it will be seen, that the proportionate weight 

 of the spleen to that of the whole body in- 

 creases very rapidly in the embryo, and is 

 almost as great at the period of birth as in the 

 adult ; from which it sufficiently follows, that 

 the spleen is an organ, the activity of which 

 extends from the end of the fcetal period 

 through the whole life, and reaches its highest 

 point in middle age. 



As regards the function of the spleen, of 

 the innumerable theories and hypotheses re- 

 specting it, only a very few deserve a nearer 

 consideration ; namely, only those which place 

 the spleen in intimate relation with the life of the 

 blood. In point of fact, almost all the facts 

 which with greater or less certainty we know 

 concerning the spleen, and, above all, the ana- 

 tomical ones, point to such a relation. Hew- 

 son had already stated, that when an organ 

 receives more blood than it requires for its 

 own nutrition, we may conclude therefrom 

 that that blood undergoes a change in it, or a 

 secretory process takes place ; and this ex- 

 pression will not apply to any organ in the 

 body better than to the spleen, which must be 

 considered as relatively better supplied with 

 blood than any other organ. Therefore since 

 all pathological, anatomical, and physiological 

 facts prove a relation of the spleen to the 

 blood, we may securely assume, that a change 

 of the blood takes place in the spleen. The only 

 difficulty is to know what change. Firstly, 

 the blood may either suffer a change in its 

 transition from the arteries to the veins ; or, 

 secondly, the separation of a particular lymph 

 from the blood may take place in this organ. 

 It is well known that the latter view was first 

 maintained by Hewson *, who at the same 

 time announced that the lymph generated in 

 the spleen serves to form blood corpuscles ; 

 and since then, Tiedemann and Gmelin have 

 specially supported the same view. But the 

 grounds adduced for this theory seem to me 

 to be insufficient. At one time, the great quan- 

 tity of lymphatics in the spleen was brought 

 to prove that a special lymph was developed 

 here. But that part of the spleen on which 

 special stress is laid, namely, the interior or 

 parenchyma, is quite poor in lymphatic vessels ; 

 .and its surface, even in the lower animals, 

 scarce contains more of such vessels than 

 other organs ; to wit, the peritoneum covering 

 the liver, the pleura covering the lungs, 

 &c. Therefore the formation of a special 

 lymph by the spleen can as little be assumed 

 as in the case of the lungs and liver. Se- 

 condly, the red colour of the spleen-lymph, 

 .and its greater coagulability, have been ad- 

 duced as proofs of a peculiarity, and of a 

 blood-forming import. But it may be de- 

 manded, are these properties constant, and on 



* Opus posthumum, sive rubrarum sanguinis par- 

 ticularum thyrai et lienis descriptio, 1786. 



what do they depend ? As to the first ques- 

 tion, it is certain that a red colour of the 

 spleen-lymph is, on the whole an exception, 

 as Seiler and Ficinus* formerly stated. In 

 rabbits, cats, or dogs, I have never found such 

 a colour, and have also always found the chyle 

 of the thoracic duct of only different shades 

 of white. But I will not deny that in calves 

 and sheep a reddish spleen-lymph is often 

 found, and I will add that this is frequently 

 the case in the horse. But this is sometimes 

 the case in other organs, as, for instance, in 

 the liver and in the lacteals, where Tiedemann 

 and Gmelin in some cases also found a reddish 

 and very easily coagulable fluid ; and it is im- 

 portant to observe, that the reddish colour 

 and easy coagulability in these cases depend 

 simply on blood which is mixed with the 

 lymph. Thus, if the reddish spleen-lymph of 

 a calf be examined, a quantity of fully de- 

 veloped blood corpuscles are found in it, 

 which are altogether identical with those in 

 the blood.f Now since it cannot be as- 

 sumed that real coloured blood globules are 

 formed in the lymphatic vessels of the spleen, 

 and since, in point of fact, all trace of such a 

 developement of blood globules is absent, it 

 will only follow from the facts adduced, that 

 in the cases of reddish spleen-lymph a mixture 

 of real blood and lymph has taken place. This 

 mixture may be the result of normal anas- 

 tomoses between lymph and bloodvessels, or 

 may owe its origin to a rupture of both these 

 vessels. I believe the latter to be the case, 

 and am simply of the opinion that it is not at 

 all to be wondered at. For in Tiedemann's 

 cases the animals were either killed by a blow 

 on the head, or died during convulsions ; and 

 it is not surprising that during such a death- 

 struggle an organ so richly supplied with 

 blood as the spleen should make an abnormal 

 path for that fluid, or that a similar thing 

 should happen when the vena porta has been 

 tied. It is well enough known, how easily 

 the lymphatics of the spleen are filled by an 

 injection into the bloodvessels. The reddish 

 colour and easy coagulability of the spleen- 

 lymph in particular cases therefore proves 

 nothing at all, except that, on account of its 

 great vascularity, blood is more easily extra- 

 vasated in the spleen than elsewhere, and 

 enters the lymphatic vessels. Thirdly and 

 lastly, Tiedemann and Gmelin adduce the 

 above-mentioned course of the lymphatics in 

 the tortoise as a powerful proof of their view ; 

 but Rudolphi J found exactly the contrary, 

 since in two large sea-tortoises not a single 

 lymphatic of the intestine passed to the spleen, 

 but they all went directly to the thoracic 

 duct. 



In consequence of what has been said 

 which I might also corroborate by many other 

 facts could I go more into detail it is im- 

 possible to imagine the development of a 

 special lymph in the spleen ; and hence the 



* See Giesker, S. 265. 



f See also Nasse, (Wagner's Handworterbuch der 

 Physiologic, Band ii. S. 370.) 



J Physiologic, Band ii. Heft 2. S. 156. 



