790 



SPLEEN. 



penis. Special cells or cavities do not 

 exist. 



So far J. Mliller. If we now ask ourselves 

 the reason of these important differences be- 

 tween these two authors cited, one of whom 

 affirms the continuation of the tufts in the 

 pulp, and a connection of Malpighian cor- 

 puscles with arteries and venous interstices 

 only ; while the other denies all this, we shall 

 find it not very difficult to give an answer. 

 Giesker, in his description, limited himself to 

 the appearances met with in the human subject, 

 while J. Mliller made the pig and the ox the 

 basis of his delineation. This circumstance will 

 at least partially explain the want of corre- 

 spondence in the two descriptions ; for I find 

 that between the spleen of man and that of the 

 animals mentioned considerable differences 

 exist. 



In man, at least generally, the arteries to- 

 gether with the veins pass deeply into the 

 substance of the spleen, lying in the same 

 sheath with them, and exactly following their 

 course. According to Giesker, the two classes 

 of vessels accompany each other even to their 

 final ramifications ; but this is not correct. 

 In every spleen instances occur, which are 

 easily seen, where small veins and arteries lie 

 very close to each other ; and Giesker has 

 evidently allowed himself to regard these par- 

 ticular instances as the rule, and has ex- 

 tended it as a description to the smallest 

 branches of vessels. But if an arterial and 

 venous primary branch be successive!}' fol- 

 lowed to their minutest ramifications, it will 

 be seen that, sooner or later, every artery and 

 vein, without exception, separate from each 

 other, and follow their special path. It is not 

 at all unusual to find this even with arteries 

 from |- to 1 line in diameter, but it is always 

 the case with those of from l-10th of a line. 

 In such an instance the artery, setting out 

 alone, does not perforate the sheath in which it 

 hitherto lay, but takes with it a distinct yet 

 often inseparable covering of the same ; so 

 that from this point forwards a special and se- 

 parate venous and arterial sheath exist. And 

 in man the Malpighian corpuscles lie only on 

 these isolated arteries ; a state which Mal- 

 pighi and MUller had already described in 

 Mammalia. 



As regards the other circumstances of the 

 arteries, I have found them exactly as MUller 

 describes them in the lower animals. After the 

 smaller branches of the arteries are connected 

 with the Malpighian corpuscles, they enter into 

 the red spleen substance, and immediately upon 

 this each small trunk spreads out in the shape 

 of a tuft into a large number of yet finer arte- 

 ries (fig. 526, rf.) ; and these tufts or pencils 

 of arteries, lying in great numbers close to 

 each other, give to the terminations of the 

 arterial trunks a very beautiful appearance, 

 which may be best compared to the broad 

 crown of a (pollard} tree. These separate 

 tufts, dividing and diminishing in size yet 

 more, terminate by an immediate transition 

 into the true capillaries ; which, in a more 

 and most minute form, of 3 to 5-1000ths 



of a lirie, constitute a close and beautiful 

 network in the separate portions of the 

 pulp, and in those parts of it which sur- 

 round the Malpighian corpuscles ; although 

 they do not form a special vascular covering 

 for the same. Many authors seem to deny 

 the existence of capillaries in the spleen : 

 thus Engel * has lately altogether denied them ; 

 but this is quite erroneous. They may easily 

 be seen in the pulp of the human spleen, by 

 the aid of the microscope, both empty and 

 filled with blood, and exhibit themselves as in 

 no way different from the capillaries of other 

 organs ; and the finest of them have a dia- 

 meter of only 3-1000ths of a line. J. MUller 

 is also in error when he describes the arteries 

 as coursing through the coats of the Mal- 

 pighian corpuscle, since they always pass on 

 its exterior. Finally, Giesker is wrong in 

 describing the arterial pencils as spreading 

 themselves out on the Malpighian corpuscle, 

 and here becoming continuous with the veins ; 

 even in man it is not difficult to discover that 

 the pencils only begin beyond the corpuscles, 

 that they lie in the pulp, and that it is here 

 they first break up into capillaries. 



Giesker at least partially agrees with this 

 statement when he says f that the pulp con- 

 sists of nothing but the minutest arteries and 

 veins united by fibrous tissue. The sheaths 

 of the vessels above described are just as much 

 more delicate as are the vessels themselves, 

 and they are finally lost as distinct coats on 

 the capillaries ; here they form delicate fibrous 

 membranes which connect the capillaries to- 

 gether, and under this form they pass through 

 the whole of the pulp. 



As to the veins, I must first, with Giesker, 

 express myself in the most decided manner 

 against all the more ancient and modern ana- 

 tomists who suppose and describe venous 

 spaces (sinus venosi) in the human spleen. I 

 have bestowed the greatest attention to the 

 dilated commencements of the veins in ques- 

 tion, and it was only my own researches that 

 led me to renounce the opinion that these 

 dilatations really exist ; indeed I have never 

 been able to discover anything special or ex- 

 traordinary about these veins. Firstly, as to 

 the larger veins, which are as yet accom- 

 panied by the arteries, there is nothing very 

 remarkable about them, with the exception of 

 their considerable size, which has been already 

 mentioned. They all have a membrane which 

 is continuous with that of the smaller veins, 

 and is least separable on that side with which 

 the artery is in contact ; this membrane is 

 only distinguishable from the sheath of the 

 vessels by its greater delicacy, and in com- 

 pany with this sheath it gradually diminishes 

 its thickness. Orifices of the smaller veins, 

 constituting the so-called stigmata Malpighi, 

 are present in very small numbers in the 

 larger veins ; while, on the other hand, they 

 are somewhat more frequent in the smaller of 

 the vessels in question. When the veins 



* Zeitschrift der Gesellschaft der Aerzte in Wien, 

 1847. 

 t Loc. cit. S. 166. 



