284 FIRST PRINCIPLES OF NATURAL CLASSIFICATION. 
distinct species. Before naturalists had discovered the 
necessity of that nice examination which is now so es- 
sential, it was customary to depend more upon the 
general aspect of an animal, than upon its minute de- 
tails of structure ; and in this way it not unfrequently 
happened that a host of true species were classed as 
varieties. Experience, however, has now taught us 
that the productions of every quarter of the globe have 
a marked and peculiar character; and that, although 
there are, for instance, some species of birds or insects 
common alike to the Old and the New World, yet that. 
this wide geographic range is enjoyed by so very few, 
that they became rare exceptions to one of the most 
prevalent laws of nature. As a striking instance of 
this, we may cite the lions ; which naturalists, up to this 
day, have viewed as constituting but one species. The 
fact, however, will turn out to be, that there are no 
less than five, if not six. One inhabits the north of 
Africa, and is that species best known to the ancients 
(Leo Africanus Sw.): another, now in the Surry Zoo- 
logical Gardens, is peculiar to Asia; and which, upon 
its arrival, was examined and designated by me as the 
Leo Asiaticus* : the third is the black-maned lion, 
mentioned by Mr. Burchell (Leo melaceps Sw.) ; and 
the fourth is the lion of Southern Africa (Leo Australis 
Sw.). In like manner, we have ascertained that the 
giraffe of Northern Africa (Camelopardalis Antiquorum 
Sw.) is quite distinct from that of the southern part of 
. the same continent (Cam. Australis Sw.). The hare of 
Europe, again, according to Mr. Gray, seems to be a 
different species from the hare of Nepaul: while very 
many of the lepidopterous insects of North America, 
until their larvee were made known by Abbot and Smitht, 
were considered identical with those of Europe. On 
the other hand, too much stress must not be laid even 
™ * The description and name of this species were communicated from 
these gardens to the editor of the ‘‘ Naturalist’s Library,” but no allusion is 
made to the previous examination and name | had given it. 
+ The Lepidopterous Insects of Georgia. See Introductory Discourse, 
on Nat. Hist. p. 66, 
