438 Scientific Intelligence. 
existence coincident both in time and space with preéxisting closely allied 
species.” Edward Forbes, who may be called the originator of this 
other than the same laws, whatever these may be. 
n. In an 
mentary treatise published in the year 1835, he adopted and, if we rightly 
remember, vigorously maintained, Schouw’s idea of the double or multi- 
ple origin of species, at least of some species,—a view which has been 
carried out to its ultimate development only perhaps by Agassiz, 1m the 
denial of any necessary genetic connection among the individuals of the 
same species, or of any original localization more restricted than the area 
hem so curious and extraordinary, of the actual geographical je 
tion of the species. In the present essay, not only the distribution b ; 
mething derivative; 
: while some 
noually 
i) 
favorable to Heer’s view. . 
As an index to the progress of opinion in the direction referred tO nf 
will be interesting to compare Sir Charles Lyell’s well known se de 
20 or 30 years ago, in which the permanence of species was ably ai 
tained, with his treatment of the same subject in a work just Issue® 
England, which, however, has not yet reached us. with 4 
A belief in the derivation of species may be maintained along ee 
conviction of great persistence of specific characters. This is the 
= tiene Swiss vegetable paleontologist, rea ni Pipes e 
len change of specific type at certain periods, and perhaps me 
Pictet. ee atone silat views in his elaborate eo 
on Elephants, living and fossil, in the Nutural History Review forte 
ary last. Noting that “there is clear evidence of the true Mam drift 
having existed in America long after the period of th forts? 
when the surface of the eountry had settled down into its present Bk, 
_ and also in Europe so late as to have been a cotemporary of the Irish 
ion of 
a 
