2 THE SENSE OF TOUCH IN ANIMALS 



experimenter and the animal which is the subject of his ex- 

 periments, does not well lend itself to purely physiological study. 

 We do not know yet the language of any ape or monkey in spite 

 of Garner's researches into the subjects in tropical forests, and 

 though in the case of some of the domesticated animals, we might 

 obtain some useful results, the prospects here are very limited. 

 There is, no doubt, a field of this nature to be worked by the 

 physiologist ; and it is with a view to providing some anatomical 

 materials for the study of the sense of touch in the lower am"mal 

 that this work has been undertaken. The facts here described 

 are purely anatomical, and no disrespect to the great department 

 of biology, called physiology, should be supposed, because a 

 physiological subject is treated upon anatomical hues. The 

 two departments of biology, anatomy and physiology, are only 

 to be studied apart from one another because of the growing 

 complexity of the physiological side, and the slowly increasing 

 knowledge of anatomy, so that specialisation is necessary, but 

 not because of their essential difference. 



In such a subject as we have before us it is legitimate to do the 

 best one can with the material provided by Nature, and in the 

 investigation of the palmar and plantar surfaces of many animals, 

 there is found a very great variety of the epidermis and the 

 corium, which demands an interpretation. The hand and foot 

 being the most general and most important parts of the bodies of 

 Mammals and Birds concerned in the sense of touch, these parts 

 deserve particular examination. 



The methods pursued concern two orders of phenomena, the 

 macroscopical and the microscopical modifications of the skin. 

 The former chiefly deals with the description and illustrations 

 of the papillary ridges found on the palmar and plantar surfaces 

 of eighty-six Mammals, and these ridges are shown in drawings 

 taken from the species examined. 



A short, general description of the character of the surface of 

 the palmar and plantar skin in all the species is also given, not 

 only in those which present papillary ridges, but in others, such 

 as Marsupials, Rodents, Carnivores and Insectivores, in which 

 papillary ridges are seldom to be found. This examination 



