CHAPTER XVII. 



VARIETIES OF EPIDERMIS. 



Passing now to the smaller trenches of the front line I have chosen 

 as the first of them a small study of the varieties of epidermis 

 found in mammals. With the exception of aquatic mammals 

 so few of this, the greatest vertebrate class, are not clothed with 

 hair that it is only on the comparatively hairless body of man, 

 with its third of a million fine hairs, that the varieties of epidermis 

 can be broadly studied. Much of this chapter will resolve itself 

 into a consideration of the palmar and plantar surfaces of certain 

 mammals, where no hairy covering obscures the operation of 

 stimulus and response. 



I assume that the foregoing phenomena of hair-direction have 

 chosen and raised on his shield their own king. But here I must 

 ask of the succeeding groups when they say, " I am, Sir, under the 

 King, in some authority," the question, " Under which King, 

 Bezonian, speak or die " — 



Shall it be Darwin's Personal Selection ? 



Roux's Cellular or Histonal Selection % 



Wallace's and Romanes' Sexual Selection ? 



Weismann's Germinal Selection % 



The rule of Mendel % 



Selection of mutations according to de Vries % 



Or shall it be the barbarian king Plasto-diethesis ? 



Which indeed of the seven kings will they choose, if I may 

 thus personify them ? I may, perhaps, urge on them the mild 

 and tolerant rule of Lamarck and Darwin rather than that of the 

 other anointed sovereigns, hoping this cannot be taken as an 

 attempt to influence the jury through the Press in a case which 

 is still sub judice. 



Stimuli and Response. 



The skin over the trunk and limbs of man is exposed to stimuli 

 of pressure, friction, heat, cold and wind in very different degrees, 

 according to the part which it covers . I do not here refer to nocuous, 

 or so-called noci-cipient stimuli, as being too casual in their incidence 

 for the question in hand. Broadly the ventral surface of the neck 



