THE SPLEEN. 155 



still be easily detected in the very smallest vessels that can be 

 be isolated by dissection. I find dilatations of any kind in no 

 part of these veins, only, it is to be observed that they become 

 narrowed more slowly than the arteries. Their continuity with 

 the capillaries takes place in exactly the same manner as in all 

 other organs and may be demonstrated without difficulty, by 

 injecting the veins of a well preserved human spleen, especially 

 of a child. Neither does any trace of dilatations present 

 itself in this case. 



The capillaries of the spleen have the ordinary structure, 

 and a width of 0-003'" — 0-005'"; they are very numerous, and 

 exist throughout the pulp, where, round the Malpighian cor- 

 puscles, though not in their coats, and elsewhere, they form a 

 tolerably close network continuous through the whole spleen, 

 only interrupted by the minutest trabecules and by the Mal- 

 pighian corpuscles, 



The human spleen possesses, relatively, very few lymphatics. 

 The superficial set are distributed sparingly between the two 

 coats, but can hardly be recognised, except in the neighbour- 

 hood of the hilus and in perfectly healthy spleens. The deep 

 set may be discovered in the hilus, whence also, few in number 

 and small in diameter, they accompany the arteries, but cannot 

 be traced by any means so far as these. In the hilus both sets 

 of lymphatics join, traverse a few small glands, which exist 

 in this locality, and finally unite into a trunk which opens into 

 the thoracic duct opposite the 11th or 12th dorsal vertebra. 

 In diseased spleens no trace of the superficial lymphatics can 

 ordinarily be detected. 



The nerves of the spleen, consisting of many fine and a few 

 thick tubules, with a moderate proportion of Remains fibres, are 

 derived from the splenic plexus, formed by two or three trunks 

 which surround the splenic artery, and are continued on the 

 arteries into the interior of the organ, each dividing into one or 

 two branches, anastomosing here and there. In the Sheep and 

 Ox, these splenic nerves are truly colossal, so that, taken toge- 

 ther, they equal the empty and collapsed splenic artery, this 

 size, however, being attributable principally to the unusual 

 quantity of Remakes fibres. 



In animals, these nerves, which never possess ganglia, may be 

 followed into the spleen further than in Man; and, by the 

 aid of the microscope, I have frequently met with them even 



