138 SPECIAL HISTOLOGY. 



0-006— 0008'" in length, and 0-002'" in breadth. In the walls 

 of the pancreatic duct, and its larger branches, small racemose 

 glands of 0-06— 0-08'" with vesicles of 0016 — 0'02"', and a less 

 fatty epithelium, are situated in considerable numbers; whether 

 they are mucous glands analogous to those of the biliary ducts, 

 or parts of the pancreas itself, I cannot say. The pancreas 

 possesses the ordinary investing tissue of the glands, with more 

 or less abundant fat cells, in which the vessels and nerves of the 

 gland are distributed. The former present exactly the same 

 relations as in the parotid, except that the lymphatics appear to 

 be more numerous; the latter would seem only to accompany 

 the vessels and arise from the sympathetic, possessing fine, and 

 a few moderately thick tubules. The secretion of the pancreas 

 is normally perfectly fluid, only accidentally containing formed 

 constituents, as detached epithelium of the glandular vesicles 

 and of the ducts. 



The development of the pancreas commences by the forma- 

 tion of a diverticulum of the posterior wall of the duodenum 

 and in its further progress, exactly resembles the salivary glands, 

 except that the rudiment of the gland forms, from the first, a 

 more compact mass and thence is not so readily made out in 

 detail. 



[The examination of the pancreas presents no difficulties, 

 except that, in Man, the fat in the epithelial cells of the 

 glandular vesicles offers some impediment and therefore the 

 pancreas of Mammalia (Rabbit, Mouse), which usually contains 

 less fat, should be made use of. The glandules in the ducts 

 are best rendered visible by acetic acid.] 



OF THE SPLEEN. 



§165. 



The spleen, is a so-called blood-vascular gland, which is in 

 some way concerned in the renewal of the blood and probably 

 with the secretion of the bile also. It consists of a fibrous and 

 serous coat and of a soft parenchyma, the latter being princi- 

 pally composed of reticularly interwoven solid bands, the 

 splenic trabecules, inclosing a red substance, the splenic pulp. 



