HABITS IN MAMMALS. 



tion of the primitive characters of small size, generalized (/. c. 

 short, more or less plantigrade, pentadactyl) limbs with moder- 

 ately sized claws and normal relations of the radius and ulna, 

 clavicle and muscles used in digging unreduced, face pointed 

 elongate, dentition adapted to food found in the earth. Hence 

 it is natural that the majority of fossorial forms should have 

 sprung from primitive and defenceless rodents, insectivores and 

 edentates and that the carnivores (especially those with special- 

 ized sectorial dentition) the ungulates (mostly herbivorous, and 

 cursorial), the primates (typically light limbed, light clawed, 

 short faced), have as a rule failed either to find protection 

 from foes or abundant food by turning into the barred road of 

 fossorial modification. 



