2 3 



individuals ? If all our tissues, whether in health or disease, 

 are subject to heredity, I do not see why this comparatively 

 rare condition whether dependent upon vascular or vaso- 

 motor change, should not occasionally be evolved in the 

 case of certain individuals, as the result of complicated 

 tissue proclivities which have been inherited. Until, 

 however, the exact pathological conditions which engender 

 purpura are thoroughly established, I am content to allow 

 this affection to remain amongst the category of those whose 

 dependence upon heredity is "not proven." It should 

 not, moreover, be forgotten that a purpuric condition is 

 also associated with scurvy, and that this latter affection 

 is included amongst the diet-diatheses by Mr. Jonathan 

 Hutchinson. 



Amongst the neurotic affections of the skin are included 

 hypersesthesia, anaesthesia, and pruritus. The two first are 

 so evidently dependent upon neurasthenic or neuropathic 

 conditions, which are admittedly hereditary, that they need 

 only be mentioned ; and the latter can only be included 

 amongst those cases of idiosyncratic susceptibility in which 

 the skin is inherently hypersensitive, as manifested by the 

 different results produced upon different individuals by the 

 bites of various insects, contact with woollen clothing, etc. 

 Of those cutaneous affections depending primarily on 

 deposit or alteration of pigment, and including melasma 

 and leucoderma, nothing much can be said, as nothing 

 definite is known as to their causation. They are, however, 

 of little importance, and what I have said as to purpura will 

 apply equally to them. It may, however, be remarked that 

 certain individuals and families are more subject than others 

 to the forms of pigmentation resulting from exposure to the 

 sun, and that chloasma gravidarum characterises many 

 families during the pregnant state. 



