424 



STRUCTURE OF THE SKIN 



a net-work of vessels, which thoy believe to be lymphatics 

 mixed up with veins, spread upon the surface of the derm.* 

 i, The organs which secrete the mucus, of which the rete mu- 

 cosum and cuticle is formed, or blennogenous apparatus ; this 

 consists of a glandular parenchyma situated in the thickness of 

 the derm, and of short excretory canals 7i, which deposit the 

 mucous matter between the bases of the papillas. The chro- 

 matogonous organs or glands, which secrete the coloring 

 matter or scales, run parallel with, and immediately below the 

 grooves on the surface, and between the papilli, which they 

 are also placed a little below. The ends of them, marked by 

 a collection of dots, can of course only be seen in the plan, in 

 consequence of their running parallel with the grooves, and 

 between the parallel ranges of papillas. 



— They consist of a glandular parenchyma, receiving an abun- 

 dance of capillary vessels from the derm below, and possessing 

 excretory canals above, that throw upon the surface of the 

 derm, the coloring principle, which is mixed with the soft and 

 diffluent corneous or mucous matter, secreted by the blennog- 

 enous apparatus. From this mixture results the pretended 

 rete mucosuni of Malpighi, and the epidermis or cuticle. 

 From this apparatus is also produced, they think, the horns, 

 scales, spines, bristles, hair, wool, hoofs, nails, etc. of different 

 animals. It is solidified in successive couches, to the right and 

 left, as seen in the section across the grooves, /; but in the 

 longitudinal section m, these layers present a series of straight 

 lines one above another like the leaves of a book. 

 — In consequence of this arrangement, the corneous matter, 

 when macerated, throws off layer after layer. The superior 

 face of the epidermis presents grooves, as represented at n, 

 which correspond to the interpapillary grooves of the derm. 

 0, Are the prominent ridges in the cuticle formed over the 

 papillae, separated by transverse grooves, p, at the bottom of 

 which are found the pores of the sudoriferous canals, e, Are 



* The existence of these inhalent vessels, from some observations I have 

 made with a very powerful microscope, I should consider extremely doubtful. — p. 



