hologist,
the late M. Bourguignat, with regard to introductions of mollusca.
Whether he had any actual facts collected in support of it, I cannot
say, but he maintained that species accidentally transported, with the
exception of those under maritime influence, can only be acclimatised
from north to south, and not from south to north--from east to west, but
not from west to east (p. 353).

The whole theory of the accidental or abnormal dispersal of mollusca
appears to have been originated by Darwin, in order to account for their
presence on so-called _Oceanic islands_. His views were strongly
supported by Wallace, who defines these islands (p. 243) as those which
are of volcanic or coralline formation usually far from continents,
entirely without indigenous land mammals or amphibians, but with a fair
number of birds and insects, and usually with some reptiles.

I do not wish it to be understood that I am in any way undervaluing the
great works of these distinguished naturalists. Darwin's views have had
more influence in advancing Zoology than those of any man, and his fame
is unassailable. Nevertheless, I feel that his theories regarding the
origin of the faunas of oceanic islands require revision.

The formerly prevalent belief of the permanence of ocean basins has been
shaken by the utterances of some of the greatest geologists of our day,
whilst many positively assert that what is now deep sea of more than
1000 fathoms was dry land within comparatively recent geological epochs.
Thus the Azores are classed by Darwin and Wallace among the oceanic
islands--that is to say, among such as have received their fauna and
flora by flotsam and jetsam. But Professor Neumayr believes, on
geological grounds, that the Old and New Worlds were connected by a
land-bridge during Tertiary times right across the Atlantic, and that
the Canary Islands, Madeira, and Azores (p. 547) are the last remnants
of this continent. This meets with the entire approbation of Dr. von
Ihering, who has recently re-investigated the subject from a faunistic
point of view (p. 135). Take another instance of one of Wallace's most
typical oceanic islands, the Galapagos Group. Their fauna and flora have
recently been most thoroughly re-explored by an American expedition, the
result of which, according to Dr. Baur, goes to show that these islands
must have formed part of the mainland of South America at no distant
date. The fauna and flora are therefore to be r