37 2 THE SPLEEN HLASEK's VIEWS. [sect. 169. 



o - i7"' only. The larger lymphatics, in most animals, accompany the arteries. 

 How they commence is unknown ; and I can only affirm, that the arteries 

 which bear the Malpighian bodies and the ultimate tufts are no longer accom- 

 panied by any lymphatics recognisable by the microscope. The structure of 

 the lymphatics of the spleen offers no peculiarity ; they are provided with 

 valves. 



The arteries of the human spleen are very muscular, and this completely 

 suffices to explain the well-established increase and decrease which takes 

 place in the size of the organ five or six hours after taking nourishment. Iu 

 animals, the muscular fibres of the envelope and of the trabeculae may also take 

 part in this phenomenon, and their existence here will also explain how it is 

 that spleens of animals contract more energetically, when galvanised than the 

 human spleen ; still, even in this latter, contractions do occur, as has recently 

 been observed in Wurzburg in an executed criminal (see Wiirz. Verh. v.). 



Quite recently, Illasek has brought forward very peculiar opinions on the 

 structure of the spleen. According to this author, there exists no independent 

 red splenic substance, but it lies wholly in the interior of anastomosing venous 

 spaces ; and these spaces, covered by a regular epithelium, traverse the whole 

 spleen and constitute its chief substance. The other parts of the spleen, 

 envelope, trabeculae, capillaries, nerves, splenic corpuscles, and lymphatic 

 vessels, lie external to these cavernous veins, and contribute to the formation 

 of their walls. How the capillaries are related to these venous spaces Illasek 

 does not state, but, in the opposite direction, he believes that the larger veius 

 arise from the spaces by means of roots. Now, I hold this view of the 

 structure of the spleen to be wholly incorrect, although it explains so plau- 

 sibly the relation of the pulp to the formation of blood-corpuscles, and will 

 be held to furnish a ready explanation of leucaemia in tumours of the 

 spleen. Nothing is easier than to show that the cells of the pulp do not lie 

 in spaces lined by epithelium, for they are everywhere directly in contact 

 with the trabecuke and Malpighian corpuscles — with the arteries, veins, and 

 capillaries — with the nerves and sheaths, and on these parts there is as- 

 suredly no epithelial covering. From this it results, that the. chief substance 

 of the spleen certainly does not lie within blood-vessels ; Illasek, indeed, 

 would explain the pulp as simply blood very rich in cells, ignoring the fact, 

 that the splenic pulp has a strongly acid reaction, while the blood in the 

 splenic vessels is alkaline as usual. Without asserting, therefore, that the 

 mode of connexion between the capillaries and veins is positively made out, 

 and without being prepared to state the exact relations of the cavernous venous 

 spaces of ruminants (the existence of which in these animals and in the horse 

 I admit), I am perfectly convinced that the account of the vessels given by 

 Illasek is incorrect. 



Virchow and myself have recently established the fact, that elements of 

 the splenic pulp (cells containing blood-globules, pigment-cells, simple pulp- 

 cells, and pulp-cells with several nuclei) do pass into the blcod-vessels, and, 

 conversely, that normal blood-cells, as well as others in process of destruction, 

 constantly occur in the pulp. There is, therefore, no room for doubt that the 

 spaces which contain the splenic pulp stand in some normal relation with the 

 blood-vessels ; and the question then remains, which of the two theories we 

 are to adopt: 1. the view expressed by me in a previous section, that a 

 part of the arteries and veins are connected in the usual manner through capil- 



