550 APPENDIX. 



The dermic portion of the duct is also of a somewhat co- 

 nical shape, its base being in like manner directed upwards, 

 and its parieties being continuous with the basement mem- 

 brane of the dermis ; this portion, therefore, is of a totally 

 different structure from the former ; it is described by 

 Mr. Rainey as being lined by a layer of epidermic scales, 

 which get gradually indistinct towards the gland, and its 

 upper or expanded part as receiving the termination of the 

 epidermic division of the duct. 



This description of the duct of the sudoriparous gland, so 

 far as I have been able to follow it, would appear to be in 

 its main particular correct, it consisting, as stated, of two 

 portions, an epidermic and a dermic ; the former is scarcely 

 to be regarded, however, as anything more than an appendage 

 to the dermic part, which is the true duct, it being little more 

 than a definite channel through the epidermis. 



It seems to me, however, to be incorrect to describe the 

 epidermic portion of the duct as commencing in the deep 

 layer of the epidermis ; it extends beyond and far deeper 

 than this, for it lines the whole length of the true duct, and 

 this not merely with loosely aggregated cells, but these are 

 so united together as to form a distinct tubular membrane, 

 which by maceration may be exhibited as such (see Plate 

 XXIII. Jig. 2.); the epidermic cells become, in fact, con- 

 tinuous with those of the sudoriparous gland itself. 



Mr. Rainey has noticed the fact that the secretion of the 

 sudoriparous glands in the palms of the* hands and soles of 

 the feet, where the sebaceous glands are entirely wanting, is 

 of a greasy character ; from this circumstance he draws the 

 conclusion that these glands secrete both sweat and sebaceous 

 matter, the former in their more active state, the latter in 

 their less active condition. 



It is only in the hands and feet, where the epidermis is 

 thick, that the epidermic portion of the sudoriparous duct 

 assumes importance. 



