78 



THE SENSE OF TOUCH IN ANIMALS 



plantar surfaces. Many of the papillae of the corium shown in 

 the illustrations are doubtless vascular, and not nerve-papillae, 

 but the broad fact remains undeniable that the papillary layer 

 of the corium is essentially a sentient and tactile structure. 



Imhrication. — The preceding diagram (Fig. 52a) which is 

 copied from " Quain's Anatomy " (after Kolhker) shows the 



Fig. 52b. — Section of skin of Macacus cynomologfs. Copied from 

 O. Schlaginhaufen's paper in Morph. Jahrb. (Gegenbauer), vol. xxxlii. 



a, stratum comeum ; h, stratum malpighii ; f , corium ; d, crest of papillary 

 ridge; ee, furrow of papillary ridge; /, opening of^ sudoriparous duct; 

 (J, diiisenleiste ; h, cut blood-vessel; i, duct of sudcriparous gland; 

 j, papilla of corium ; /;, papilUe of corium. 



papillary ridges of the epidermis of an even character, very much 

 hke the ridges and furrows of a ploughed field, and in many parts 

 of the palmar and plantar surfaces of man, and in many other 

 species this description is correct. The ridges rise out of the 

 furrows at equal angles on the two sides. But in the course of 

 examination of the human skin with a lens, I found that this 

 rule is subject to a considerable exception. If the skin of the 

 pulps of the human fingers be looked at with a lens in a strong 

 light and in profile, it is found that the papillary ridges in some 



