STRUCTURE OF THE CORIUM. 221 



the hair follicles, and the terminal coils of the sweat glands. 

 Nerves are also present that at certain points are provided 

 with Pacinian corpuscles. Lastly, lymphatics here pursue their 

 course independently of the bloodvessels. The larger lymph- 

 atics, that present a distinct circular muscular coat, possess 

 special bloodvessels distributed to them alone, the vasa vaso- 

 rum lymphaticorum ; two such delicate bloodvessels, as a 

 rule, accompany each lymphatic, and form by their frequent 

 capillary anastomoses a close plexus around it. This explains 

 the occurrence of the sharply defined red lines in the skin, 

 which enable us to follow the course of the lymphatics in the 

 subcutaneous connective tissue in cases of lymphangitis. 



THE CORIUM. 



The corium is also composed of connective-tissue elements, 

 between which runs a double network, consisting on the one 

 hand of elastic fibres, and on the other of connective-tissue 

 cells. The fasciculi of connective tissue traversing the sub- 

 cutaneous tissue, and composed of a series of fibres, split, on 

 reaching the deeper surface of the corium, into smaller fasciculi 

 that extend in a somewhat oblique direction towards the sur- 

 face, and constantly break up into finer and finer bundles. On 

 reaching the corium, these fibres decussate with others which 

 run at right angles both amongst themselves and to the former. 

 A dense fibrous plexus, with very small meshes, is thus formed 

 meshes that, in specimens of dry skin, as well as in those 

 that have been submitted to the action of tannic acid and of alco- 

 hol, are almost invisible, but are larger in the succulent skin of 

 young persons, and attain their maximum in those pathological 

 conditions that are accompanied by exsudation. In such spe- 

 cimens we may easily convince ourselves that the fibrils enclose 

 rhomboidal spaces. 



The regularity of this arrangement is disturbed at those 

 points at which the skin is traversed either perpendicularly or 

 obliquely to its surface by various structures, as hairs, sweat 

 glands, excretory ducts, bloodvessels, and nerves, since these 

 are accompanied by a sheath of connective tissue proper to 

 themselves. 



