1 7 o PHYSIC 



constitutes a process of peripheral excretion albeit mainly 

 systemic nervine of the exhausted and effete or dried-up 

 protoplasm of the peripheral nerve terminals, admixed 

 with a proportion of haemal and sympathetic nervine 

 excretionary debris. 



Keratosis being thus an excretional process, it is, there- 

 fore, liable to stasis, arrest, and accumulation, local and 

 general, of the epidermal exuviae or excretionary materials, 

 with the result that a pathological disposal of these takes 

 place on, within, or under the epidermis on lines deter- 

 mined by the consistency of the excretory materials and 

 the histological character of the peripheral cutaneous ele- 

 ments, nervine and haemal, amid which that material is 

 arrested or deposited and keratosed, and ultimately hyper- 

 keratosed by continuous accumulation and cornification. 



A long list of skin diseases owes its genesis and exist- 

 ence to mal-excretion, or to epidermal retention or stasis, 

 and pathological arrangement or organisation of the epi- 

 dermal debris, which becomes cemented by the more fluid 

 elements of that debris, together, it may be, by the more 

 solid elements of the sweat, and is thereafter held by 

 continual mechanico-structural continuity in histological 

 union with the living textures. 



The pathological juxtaposition, union, or fusion of 

 retained excretional material, with physiologically active 

 tissue, leads to the evolution of diseased conditions of 

 great variety, each of which is determined by the operation 

 of specific morbid influences, bacterial, chemical, mechani- 

 cal, and others, and to combinations of these in different 

 orders and intensities ; all of which, operating in differing 

 constitutional conditions and under powers of resistance 

 of the most varied order, necessarily determine and secure 

 the evolution of diseased entities in accordance with the 

 laws of what may be denominated functional and struc- 

 tural survival of the strongest, but, unfortunately, not of 

 " the fittest." 



The generalisation here made applies to the evolution 

 of diseased conditions generally, as well as to that depart- 

 ment of dermatological morbidity embraced in the term 

 hyperkeratosis with which we are now concerned. 



The consistency of the excretionary material on its 



