THROUGH EUROPE AND TO THE ISLANDS OF THE ATLANTIC. 151 
within the Tertiary period, marine formations have been raised 
high into mountainous land, was cpiite ready to accept conclusions 
based on such observations ! 
No less interesting is the presence of an assemblage of land 
shells — such as Helix, Pu,pa, Clausilia, etc. — in Madeira and 
Porto Santo, botli living and fossil — and to some extent local, or 
proper to each island ; only eight of the whole being common. 
But these genera, shown to be quite indigenous, are those of the 
adjoining continental regions ; and it is inconceivable that 
they could have been imported into the islands either by human 
agency, or by those means suggested by Dr. W allace ; thus we 
are driven back to account for their presence by the hypothesis 
of an original land connection with Europe or Africa — by which 
immigration took place. 
Dr. 11. F. Scharff’ s views. — We now turn from the above 
speculations to the more reasonable views of Dr. Scharff, which, 
as will appear, are in accordance with, and go to confirm the 
conclusions deducible from recent investigations regarding the 
features of the bed of the Atlantic ocean. As I have shown 
in former papers — the rivers descending from the western 
coasts of Europe and Africa can be traced by means of the 
soundings on the Admiralty charts — to depths of 1,000 or 
1,200 fathoms below the surface — indicating the great uprise of 
the ocean bed at a very late period.* Such an elevation would 
produce land connection in the less deep areas existing between 
the mainland and the far-off islands by which animals may 
have migrated. Such land emigration is that upon which 
Scharff founds his views regarding the manner in which the 
indigenous fauna has established itself far out in the islands of 
the ocean — and, therefore, corroborates the theory of a former 
uplift founded on the existence of the submerged river- 
valleys. 
Scharff disagrees entirely with Wallace, when, after 
discussing the origin of the weasel of the Azores, he says, 
“ I am, therefore, of opinion, contrary to Dr. Wallace, that the 
existing mammalian fauna of the Azores supports the view that these 
islands were formerly connected by land with the mainland. 
It is to be recollected, however, that Scharff recognises an 
earlier period of land connection than that required for the 
migration of existing animals, probably in the Miocene period ; 
* Trans. Viet. Inst., vols. xxx, xxxi, and xxxii. 
t European Animals, p. 104. 
L 
