DISTEIBUTIOK OF OPHIDIAI^-S. 
213 
Mammals and of Keptiles, which, besides, are more adapted 
to furnish convincing proofs. The Monitor exanthemati- 
cus, and M. niloticus of Egypt and Senegal, are replaced 
at the Cape by local varieties, with colours more deep, and 
a pattern more marked ; they are then the Tupinambis 
albogularis of Daudijv, and the Lacerta capensis of Spar- 
man.* The Vipera arietans of the Cape has paler tints 
than that of Nubia or Abyssinia ; the same holds good 
with the Toad of the Cape (Bufo pantherinus, Boie), which 
there replaces the Bufo Arabicus of Egypt, with a less 
agreeable system of colouring ; the Naja Haje of Egypt is 
represented at the Cape by the Naja nivea ; and there is 
found at the Cape a variety of the Agile Lizard (Lacerta 
pardalis), which is a native of France and Spain. Certain 
Tortoises afford extremely curious examples of the influ- 
ence of climate f on animals, or of the differences which are 
often presented, in different countries, by species which are 
modelled on a single type. The great Land Tortoise of 
the Cape (Testudo pardalis, Bell) has also been brought 
from Senegal and Abyssinia ; but, instead of having its 
shield ornamented with a beautiful design in black and 
yellow, this part is of an uniform yelloAvish-grey, a tint 
which pervades all the rest of the body ; in fine, all the 
appendages of the skin have acquired, under the influence 
of so genial a climate, a stronger development ; so that 
the scales of the fore feet have all been transformed into 
points or even into spines : this local variety is known un- 
der the names of Testudo sulcata or T. calcarata. The 
Testudo angulata of the Cape, which is also found at 
Sierra Leone, has undergone, in the latter place, changes 
analogous to those which I have mentioned as taking place 
in the T. pardalis ; but, in the Tortoise, of which we now 
speak, this influence of a different climate is especially ex- 
* See the review of the genus Monitor in the third number of my 
AbbildungeUf where I have corrected the errors committed by naturalists 
in determining the species of this genus. 
t I trust that no one will compare my mode of considering the ex- 
pressions, mce, local variety^ or what depends on climate, with the ideas 
of Buffon, who would willingly unite into one species all the hares in 
the world ; or still less those of Lamarck, -who attempts to prove the 
possibility of transmutation of the orang-outan into the human species. 
