TBE APPENDAGES OF THE SKTN. 



901 



in width at their base. The nerve-papillse are the organs of touch, and con- 

 tain either the corpuscula tactus (or axile bodies) of Meissner or those of Kraiise. 



The sebaceous glands He beside the hair-follicles, each hair being flanked by 

 two glands. These small organs are composed of a very granular epithelium, 

 and are usually oval in shape. 



(They are embedded in the upper j^ ^*S- *84. ^ 



stratum of the derma, and present 

 every degree of complexity — from 

 the simplest follicle to the com- 

 pound lobulated gland. In some 

 situations, their excretory ducts 

 open independently on the surface 

 of the epidermis. Those asso- 

 ciated with the hairs are raceiform 

 and lobulated, consisting of glan- 

 dular vesicles, which open by short 

 pedunculated tubuli into a common 

 excretory duct, and the latter, 

 after a short course, into the hair- 

 follicle. In some parts the ducts 

 are short and straight ; in others, 

 where the skin is thick, they are 

 spiral. They are lined by an in- 

 version of the epidermis, which 

 forms a thick and funnel-shaped 



cone at its commencement, but soon becomes soft and uniform. Sebaceous glands 

 are met with in all parts of the body, but are most abundant in those parts which 

 are naturally exposed to the influence of friction, or require to be supple. The 

 sebaceous glands of large hairs are appendages of the follicles ; but where there 

 are soft woolly hairs, they are rather appendages of 

 the glands. The secretion — sebum — is a fatty 

 matter mixed with the debris of broken-down cells. 

 The glands are very large and numerous in the 

 sheath — preputium penis, where they are designated 

 Tyson's glands. Miiller found in the Pig a special 

 cutaneous gland, somewhat resembling the sebaceous 

 glands. It is situated on the inner and posterior 

 aspect of the knee, and is from | to ? inches in 



TACTILE PAPILLA FROM THE SKIN, SHOWING THE 



tactile corpuscles, OR " axile bodies." 

 A, In the natural state ; B, treated with acetic acid. 



Fig. 485. 



length, and from 



to 



inch in width. In the 



Sheep, there is found, in the skin between the claws, 

 a particular inversion of the integument that f onus 

 a small elongated pouch, curving upwards, and 

 terminating in a cul-de-sac. This is the inter- 

 digitalpouch, interungulate gland, sinus, or biflex canal 

 — sinus cutaneus unguJarum ,- it secretes a viscid 

 matter from glands which, according to Ercolani, 

 are analogous to the sebaceous glands. The pouch is lined with very fine hairs, 

 and often contains foreign substances, such as sand ; it sometimes becomes in- 

 flamed and its orifice occluded, when it is transformed into a retention cyst.) 

 The sudoriparous glands are deeper situated than the last (passing even into 



INTERUNGULATE SINUS OF SHEEP. 



Inner aspect of first phalanx ; b, 

 hoof, or claw; c, interungulate 

 gland ; d, ori6ce of its duct. 



