110 MALPIGHI ON THE STRUCTURE OF THE SPLEEN, 



stance, in which some of them ramify. These cords connect the 

 substance of the spleen pretty firmly to its coat, and they seem 

 to have the effect of rendering the exterior part of the substance 

 more firm and dense than the internal. They are particularly 

 conspicuous if the spleen be immersed in water, and the coat 

 pulled off while it is in that situation. The proper or elastic 

 coat of the spleen, besides sending inwards the cords above men- 

 tioned, gives off tubular processes which serve as sheaths or 

 investments to the vessels which enter it. 



The spleen has a strong resemblance to the glandular organs 

 but has no excretory duct, and its particular function is not 

 very obvious : for these reasons the structure of this organ is a 

 subject of very interesting inquiry. 



Malpighi, who took the lead in researches of this nature, 

 before injections of the blood-vessels with wax were in use, 

 after investigating the structure of the spleen by long macera- 

 tion, by boiling, by inflation, by the injection of ink or colored 

 fluids, and by examination with microscopes, declared that its 

 structure was cellular; that the cells communicated more freely 

 with the veins than the arteries ; and that they might be con- 

 sidered as appendices of the veins. He also asserted, that a 

 large number of white bodies or vesicles were to be found in 

 those cells and throughout the whole substance of the spleen, 

 which were in bunches like grapes, and preserved their whitish 

 color although the vessels around them were injected with a 

 colored fluid. This description of Malpighi appears to have 

 been admitted by some of the very respectable anatomists who 

 were contemporary with him ; but it was zealously opposed by 

 Ruysch, who exhibited the spleen so completely injected with 

 wax, that it appeared to be composed entirely of vessels.* 



Ruysch appears to have paid great attention to this subject, 

 and to have made many preparations of the spleen. From 

 these he derived the opinion, that the substance of this organ 

 was entirely composed of arteries, veins, absorbent vessels and 



* Two plates, taken from drawings of these preparations are published in 

 Ruysch's Works. One is attached to Epistola Problematica Quarta, in the 

 second volume ; and the other in Thesaurus Septimus, in the third volume. 



