Botany and Zoology. 437 
derivatives, and its attending species only provisionally admitted to that 
them species or varieties.” onceen ate are 3 fossil leaves from dilu- 
vian deposits in Sed =. she by Ga udin, which are hardly te: oie: 
able from those of Q. ur on the one hand, and gers those of @. D 
lasii, &c., of California, on the other. N6 such leaves are found in ay 
Tertiary deposit in Europe; but such are found of that age, it ap 
in Northwest America, where their remote descendants still flourish, ‘So 
that the probable genealogy of Q. Robur, traceable in Europe up to the 
commencement of the —_ epoch, looks eastward and far into the 
past on far distant shor 
Q. Ilex, the bree ae ‘Oak of Southern Europe and Northern Africa, 
reveals a similar archeology ; but its presence in Algeria leads bog 
y 4098 ite regard it as a much more ancient denizen of Europe than Q. 
R and a Tertiary Oak, ¢. ilicoides, from a very old Sissi bed in 
Switzerland, is thought to be one of its ancestral forms. This high an- 
related species in Central Asia, in Japan, in California, and even our own 
Live Oak with its Mexican relatives, may peed enough be regarded 
as early offshoots from the same stock with Q. L 
In brief,—not to continue these abstracts a ad remarks, and without 
rerence to Darwin’s particular oles (which DeCandolle at the close 
very fairly considers),—if existing species, or many of them, are ae 
ancient as they are now zie thought to be, and were subject to the 
physical and geographical changes (among them the coming and the 
going of the Glacial epoch) which this sukguity implies; if in former 
times they were as liable to variation as they now are; and if the indi- 
viduals of the same species may claim a common ocal rigin, then we 
cannot wonder that “the theory of a succession of forms by deviations of 
apr forms” should be regarded as “the most natural hypothesis,” 
ssi the ge esersh: advance made towards its acceptance in some form 
. - ot 
question being, not, how plants and animals originated, but, how 
came the existing animals and plants to be just _ they are and sickens 
they are? it is plain that naturalists interested in sach inquiri 
Mostly looking for the answer in one direction. "The general adrift of 
Opinion, or at least of expectation, is exemplified by this essay of DeCan- 
dolle; and the set and force of the current are seen by noticing how it 
carries along naturalists of widely —, views and prepossessions— 
Some faster and farther than others,—but none way. The tendency 
~ We may say, to extend the law of eet or something analogous 
to it, from inorganic to piss nature, and in the latter to connect the 
oe with the past in some sort of material connection, The general- 
ization may indeed be e xpressed #0 as not to assert that the connection is 
Sehetic, as in Mr. Wallace’s ennla: “Revere species has come into 
At. Jour, as Serres, Vou. XXXV, No. 105.—May, 1863. 
56 
