SECT. /2.] 



CEKUMINOUS GLANDS. 



l 33 



The ceruminous glands may each be divided into the glandular 

 coil and the excretory duct. The former (fig. 58) of ^ c '" to {'" to 



3 '" 



Fig. 58. 



in diameter, consists of several coils of a single canal of c/03'" to 

 006'" on an average o - 04'" to 0-05'" (-^th'" to gVth'") thick, which 

 here and there, but not constantly, presents small saccular protru- 

 sions and terminates by a blind, slightly 

 swollen extremity. A short, straight, 

 excretory duct of O'oiy'" to 0*024" ' in 

 diameter, ascends from the coil, pene- 

 trates the corium and epidermis of the 

 auditory passage, and generally opens 

 separately by a round pore of o*044'" in 

 diameter, or terminates on the upper 

 part of a hair-follicle. 



In their intimate structure the ceru- 

 minous glands are constituted as fol- 

 lows : — The tube of the glandular coil 

 possesses a fibrous coat and an epithe- 

 lium, the former 0*004'" to 0*005'" in 

 thickness, the latter 0*004'". The fi- 

 brous coat presents exactly the same 

 characters as that of the larger sudo- 

 riparous glands, i.e. it consists of an in- 

 ternal layer of smooth muscular tissue, 

 disposed longitudinally, of 00023'" to 

 o - oo26'" in thickness, and of an exter- 

 nal layer of connective tissue with scat- 

 tered nuclei and occasional very fine 

 transverse elastic fibres. The epithe- 

 lium lies probably upon a membrana 

 propria, and consists of a simple layer 

 of polygonal cells of 0*006'" to o - oi'" in 

 diameter, which contain yellow-brown 

 pigment granules, varying from im 

 measurable minuteness to 0*002'" and insoluble in alkalies and acids 

 in the cold, or whitish fat-drops measuring as high aso*ooi"'* 

 and, it is to be observed, that for considerable lengths of a gland- 

 tube the epithelium-cells contain only one and the same kind of 

 granules ; so that the glands appear either uniformly brownish, or 

 of dark colour, but in the latter case whitish by reflected light. 

 The contents of the glandular canals are sometimes a clear fluid, 

 sometimes a granular substance, consisting principally of cells, 



Section through the skin of the exter- 

 nal auditory meatus, magnified twenty 

 times, a. corium ; b. stratum Malpi- 

 ghii ; c. horny layer of the epidermis ; 

 d. coils of the ceruminous glands; e. ex- 

 cretory duct of the same ; /. their open- 

 ings; g. hair-follicles; h. sebaceous 

 glands of the auditory meatus ; t". small 

 collections of fat. 



