332 ^ LEPORIDjE. 



mediately behind the normal pair and concealed by them ; 

 the upper incisors are flat and longitudinally grooved in 

 front, while those of the lower jaw are somewhat wedge- 

 shaped. The grinders are formed for the mastication of 

 vegetable food only, being constantly worn down, and as 

 constantly growing from beneath, as in the Beavers 

 (CastoridcE) and the Porcupines (Hystricidce) ; the worn 

 surfaces are uneven and the projecting laminae of the 

 enamel transverse. The ears are long in all the species ; 

 the eyes large, prominent, and placed laterally ; the hind 

 legs, especially in the typical Hares, much longer than 

 the fore legs ; the feet hairy, and the tail short and turned 

 up. The teats are both pectoral and inguinal. The usual 

 colour is a mixture of grey and reddish-brown ; in some 

 the prevailing colour is fulvous, while in others the grey 

 predominates. The admirable wisdom which has assigned 

 such colours to a group of defenceless animals which con- 

 ceal themselves amidst the brown sombre vegetation of 

 woods and heaths, will appear more striking when it is 

 recollected that certain species, inhabiting the snowy 

 regions of the north, become wholly white in winter. 

 All the members of the genus are remarkable for their 

 timidity, and their whole structure is such as at once to 

 announce to them the presence of danger, and to enable 

 them to escape from it ; the ears and eyes are so formed 

 and situated as to become instantly cognizant of even 

 distant warnings of peril, and the limbs are admirably 

 adapted for the most rapid flight. 



With all these similarities, however, there are great 

 diversities in the habits of the different species. Whilst 

 the Rabbit excavates a burrow to a considerable depth, 

 whither it instantly betakes itself on the approach of 

 danger, the Hare makes but a superficial depression, 

 called its form, which it uses as a resting-place, and 



