3888 DIVISION I. VERTEBRAL ANIMALS.—CLASS I. MAMMALIA. 
considered as falling entirely within either of these divisions, but they may 
be looked upon as approximating to one or another of them.” 
On the above, the editor of the last edition of Cuvier’s Animal Kingdom 
offers the following observations : — 
“It appears to be conclusively proved that barbarism and insufficient 
nourishment tend, in a few generations, to deteriorate the physical charac- 
ters of even the highest races of mankind, by increasing the facial angle, 
&e., while the reverse induces proportional improvement. Still there is 
reason to suspect that the diversities which are thus occasioned are restrained 
within moderate limits; and this remarkable fact must be borne in mind 
(which I believe has not been hitherto stated), that while an artificial mode 
of life would seem to have produced those acknowledged varieties of species 
which are noticeable among such of the lower animals as have been domes- 
ticated, we observe very dissimilar races of human beings among those whose 
manner of living is least artificial of any, and which, furthermore, in numer- 
ous instances, inhabit the same countries, besides being widely diffused ; thus 
proving that climate and locality exert less influence than has been ima- 
gined. This most difficult subject of inquiry, in fine, is endlessly perplexed, 
and, in several intances, rendered quite inextricable, by the occasional blend- 
ing of two or more diverse races, in every degree of proportion. There are 
also decisive proofs (afforded by architectural relics scattered over Siberia 
and both Americas) of great nations having been utterly exterminated ; 
whose very names have perished; and if civilized, or comparatively civil- 
ized, populous nations have thus become so completely sunk in oblivion, 
that we infer their former existence only as that of some lost tribes of ani- 
mals can be recalled, how very many hordes of savages, who erect no memo- 
rials, may have been extirpated, and are forgotten irretrievably! Hence the 
extreme and apparently insuperable difficulties, which, it is probable, will 
continue to oppose the definitive solution of the intricate and peculiarly in- 
teresting problem which we have been considering.” 
