130 '.OOLOGY. 



6. Rabbit and Hare. Of all the wild animals in- 

 habiting England no one is more easily mistaken for the 

 rabbit than is the hare. Most people probably do not know 

 the one from the other by sight. The external differences 

 are slight. The hare has longer ears (tipped with black) 

 and a broader snout than the rabbit. Both limbs are 

 longer in the hare, and the fore-limbs are not so strongly 

 clawed. Again, in the rabbit the radius is shorter than the 

 humerus, while in the hare the reverse is the case; and 

 there are similar differences of proportion in other bones. 

 If we compare the skulls of the two animals, we find that 

 the hare's nasal bones, its nasal chambers, and its posterior 

 narial passage are all broader than the rabbit's corres- 

 ponding parts. It may also be mentioned that the young 

 rabbit is born naked and blind, while the young hare is 

 born hair- clad and with open eyes. 



All these features are adaptations to the different mode 

 of life of the two animals. The hare, instead of being a 

 gregarious and burrowing animal, lives a solitary life, 

 scraping a "form" (a slight hollow) in the ground, where 

 it is hidden from sight by vegetation (in a cornfield, for 

 example). Obviously a hare, living in a far more exposed 

 position, needs a keener sense of smell than the rabbit 

 (hence the differences in the nasal region of the skull), its 

 limbs need to be swift for flight, not strong for bur- 

 rowing, and its young ones must look after themselves 

 from the first. Nor, in enumerating the differences be- 

 tween the two, must we forget the differences of instinct 

 (involving differences of structure of the central nervous 

 system), without which all other adaptations would be 

 useless. 



7. Species. The rabbit and hare afford an excellent 

 example of what is meant by the terms species and genus 

 in biology. The two are said to be distinct species of the 

 same genus, which means that while they agree with one 

 another in a great many anatomical characters, they 

 differ in certain definite respects. It is necessary, for 

 precision of nomenclature, in biology, to give every species 

 a double name one being the name of its genus, or 



