14 THE SENSE OF TOUCH IN ANIMALS 



degree of corrugation which may be found with the smoother 

 form varies greatly. It has seemed simpler to place the bare 

 and corrugated epidermis in separate classes, though gradual 

 transitions between smooth and very corrugated surfaces are 

 found among these sixteen forms, and even in the same form. 

 According to the size and habits of the particular animal, the 

 epidermis is very differently modified. Thus, the smooth, 

 hard, almost shining pads of Proteles cristatus, the Earth Wolf 

 of the Cape, a clumsy, nocturnal burrowing animal like a hyaena, 

 show the epidermis of its hand and foot little modified, as one 

 might expect from its habits. Then Echidna hystrix, one of 

 the egg-laying mammals of Australia, has a hard, slightly 

 corrugated epidermis in which are set sparse strong hairs, a 

 modification in keeping with its simple burrowing habits of 

 life and primitive character. The Carnivores which exhibit 

 this type of epidermis show more variation in the way of 

 corrugation, as in Viverra civetta and Suricata tetradactyla. 

 Hydrochcerus ca/pyhara, a large stoutly-built rodent with 

 aquatic habits, has a large webbed foot and epidermis rough 

 and considerably corrugated. 



The species which represent this early and simple type of 

 epidermis are, Ornithorhynchus, Echidna hystrix, Hystrix 

 cristatus, Xerus capensis, Ccclogenys paca, Hydrochcerus capy- 

 bara, Viverra civetta, Arctigolidia trivergata, Genetta tigrina, 

 Crossarchus fasciatus, Suricata tetradactyla, Mellivora indica, 

 Herpestes griseus, Procyon lotor, Procyon cancrivorus, Hyrax 

 capensis. 



(3) Scales are among the early modifications of the epidermis, 

 and occur in nine of the eighty-six mammals examined. They 

 are found in five of the Marsupials, one Edentate, one Rodent, 

 one Insectivore, one Bat. The Coarsest of these forms is the 

 Edentate, Myrmecophaga jubata, or Great Ant-Eater, which 

 has extremely clumsy fore and hind feet covered with dense 

 epidermis modified into flat scales. These scales are not placed 

 in any definite hues or order, as those of the Marsupials are 

 in some cases. The scales of the common EngUsh mole are 

 relatively large and very strong, especially in the forefoot, which 



