PREFACE. VII 
The knowledge of the distribution of animals 
be of importance in another point of view, 
affording collateral assistance to the Geolo- 
^ ls t in determining the character of the muta- 
* lQ ns of the earth. For as at the present time 
^tiailar climates, however distant, however much 
ls °lated from each other, are peopled by similar 
^atures, so probably it has ever been; and 
ls would seem to point to a period or periods 
' v hen they were universally diffused : a diffu- 
^ l0l t which subsequent geological changes have 
er y remarkably deranged. If all animated crea- 
°U ever existed at any one epoch, the climate 
condition of the earth’s surface must have 
so peculiar, that we can form no idea of 
th 
th 
ern at the present time. While the geologists 
o l°°k to Natural History for assistance in 
^ Vln S some of their obscure problems, the 
^ralists must in turn look to Geology for 
bat 1StaUCe in deci P herin S the system which 
^ Ur e has followed in forming her productions. 
ex ' 8t ' n » races °f beings there are many 
c basms which divide creation into irre- 
^, ar masses, which have hitherto defied all 
lo >ts at successful classification. But geo- 
^' Sts are daily discovering extinct forms, which 
t^n^hng up the vacancies, and which even- 
''h \ 03 a y un 'te creation into an harmonious 
6 ^°°phytes at present existing on our 
are small and fragile when compared 
