FALCONER ON THE AMERICAN FOSSIL ELEPHANT. 
79 
But with fossil forms, this is manifestly impossible. The compass 
of a single life would hardly suffice, even, for a rigorous comparison 
of the details of the skeleton in all the geographical localities 
and geological deposits in which the remains of the Mammoth have 
been found. The observer is thus constrained to a selection. 
Through a wide range of observation on living forms, we know the 
constancy with which the characters of the teeth are maintained in 
the same species; and having faith in the order of nature, we extend 
the rule to extinct forms. The result of my observation is, that the 
ancient Mammoth of the pre-glacial ‘ Eorest-bed ’ of the Norfolk 
coast, differs less from the later form occurring on the banks of the 
Lena, than does the latter from the comparatively modern Mammoth 
of the superficial bogs of North America, which I regard as being 
only a slight geographical variety of the same species. 
The same evidence, I believe, is borne by the organs of loco¬ 
motion ; but the exposition of this part of the case is beyond the 
limits of the present occasion. 
Assuming the observation to be correct, what strong proof does 
it not afford of the persistence and constancy throughout vast in¬ 
tervals of time, of the distinctive characters of those organs which 
are most concerned in the existence and habits of the species P If 
we cast a glance back on the long vista of physical changes which 
our planet has undergone since the Neozoic Epoch, we can no where 
detect signs of a revolution more sudden and pronounced, or more 
important in its results, than the intercalation and subsequent 
disappearance of the Glacial period. Yet the ‘ dicyclotherian ’ Mam¬ 
moth lived before it, and passed through the ordeal of all the hard 
extremities which it involved, bearing his organs of locomotion and 
digestion, all but unchanged. 
Taking the group of the four European fossil species above enu¬ 
merated, do they show any signs, in the successive deposits, of a 
transition from the one form into the other ? Here again, the result 
of my observation, in so far as it has extended over the European 
area, is, that the specific characters of the molars are constant in 
each, within a moderate range of variation, and that we nowhere 
meet with intermediate forms. The specific difference in the molars, 
be it observed, rests upon a much more deep-seated foundation than 
the superficial indication, merely, of ‘ thick-’ and ‘ thin-plated ’ va¬ 
rieties. This I shall endeavour to explain with the help of figures. 
Taking Mastodon Ohioticus at one end of the chain, and E. prirni - 
genius at the other, the number of ridges in the last milk molar, and 
the three consecutive true molars, yields, in the former, the ciphers 
3 : 3, 3, 4 ; while in the latter, they rise to 12 : 12, 16, 24. The 
groups of forms interposed between these extremes, yield interme¬ 
diate numerical formulae, which are very constant in each species, 
within a moderate range of individual variation. Thus, the Mas¬ 
todon Arvernensis gives 4 : 4, 4, 5; Elephas (Lox.) meridionalis 
8 : 8, 9, 12; E. (Lox.) Africanus 7 : 7, 8, 10-11; E, antiquus 
