MALPIGHIAX CORPUSCLES OF THE SPLEEN. 



887 



Malpighian corpuscles. On closely inspecting the surface of a section of 

 the spleen, a number of light-coloured spots of variable size are generally 

 seen. For the most part these are evidently the ends of divided trabeculae 

 or blood-vessels ; but in the ox, pig, sheep, and some other animals, and also 

 in the human subject, there are found distinct whitish vesicular-looking 

 bodies, attached to the trabeculse which support the small arteries, and 

 imbedded, in groups of six or eight together, in the dark red substance of 

 the spleen. These small vesicular bodies, the Malpighian corpuscles of the 

 spleen, are capsules, varying in diameter from -^jth to -g-^th of an inch, and 

 consisting of two coats, the external of which is apparently continuous with 

 the trabecular tissue supporting the arteries. They are filled with a soft, 

 whitish, semi-fluid matter, which contains microscopic globules, resembling, 

 except in colour, those composing the red pulp of the spleen. It may ba 

 remarked, that both these kinds of globules are very like the chyle-corpuscles. 

 The vesicular bodies are attached in groups to minute arterial branches ; in 

 some of the lower animals they are sessile, but in the human spleen they are 

 pedunculated. In all cases it is established that they are expansions of the 

 sheaths of the arteries ; those which are sessile are placed usually in the 

 angle of division of two arteries, and are formed by expansion on one side 



Fig. 622. 



Fig. 622. MALPIGHIAN CORPUSCLES OP 

 THE DOG'S SPLEEN (from Kolliker). ^ 



The figure shows a portion of a small 

 artery, to one of the twigs of which the 

 Malpighian corpuscles are attached. 



only of the vessels on which they 

 are placed ; those which are pe- 

 dunculated are pierced by the 

 artery on which they are placed, 

 the expanded sheath having been 

 diffused, as it were, in the cap- 

 sule, round the vessel (Stieda and 

 Henle). Their walls pass gra- 

 dually into the pulp on the out- 

 side, and on the inside into the 

 contents of the follicle (Busk and 

 Huxley). Capillaries likewise are 

 found within them. 



The lymphatic vessels of the spleen, 

 according to Cruikshank and Mascagni, 



form a superficial and a deep set. The superficial set appear as a network beneath the 

 serous coat, receive occasional branches from the substance of the spleen, and run 

 towards the hilus. The deep lymphatics accompany the blood-vessels, and emerge 

 with them at the hilus, whence, communicating with the superficial set, they proceed 

 along the gastro-splenic omentum to the neighbouring lymphatic glands : the mode 

 in which they commence iu the spleen is unknown. The lymphatics of the human 

 spleen, at least the superficial set, are allowed by all to be very difficult to inject. 

 But even in the domestic animals, in which the process is usually more successful, 

 recent observers have not been so fortunate as Cruikshank and Mascagni. 



The splenic nerves, derived from the solar plexus, surround and accompany the 

 splenic artery and its branches. They have been traced by Remak deeply into the 

 interior of the organ. 



