A due consideration of it leads to the curious paradox that if any two animals be compared, the zoologically lower will be separated from the common ancestor by a larger number of generations, since, on the average, sexual maturity is reached more quickly by the lower form.
The northern portion of Asia, as far south as the Himalaya, is not zoologically distinct from Europe, and these two areas, with the strip of Africa north of the Atlas, constitute the Palaearctic region of Dr Sclater, whose zoological primary divisions of the earth have met with the general approval of naturalists.
The fauna of Siberia is closely akin to that of central Europe; and the Ural Mountains, although the habitat of a few species which warrant the naturalist in regarding the southern Urals as a separate region,, are not so important a boundary zoologically as they are botanically.
Zoologically, there is no distinction between mice and rats; these names being employed respectively for most or all of the smaller and larger "mouselike" and "rat-like" representatives of the Muridae, whether they belong to the genus Mus or not.
Although the name llama properly applies only to one of the domesticated breeds, zoologically it is taken to include all the South American representatives of the Camelidae, which form the genus Lama.
