Botany and Zoology. 289 
observed) it does absolutely appear, that those species, the external 
aspects of which have been thus artificially controlled, are by constitu- 
tion more tractile (and possess, therefore, more decided powers for aber- 
tation,) than the rest. Whether traces of design may be recognized in 
this circumstance, or whether those forms were originally selected by 
man on account of their pliability, it is not for me to conjecture ; never- 
theless, the first of these inferences is the one which I should, myself, 
e@ & priori inclined to subscribe to. 
a few domesticated creatures of a singularly flexible organization present, 
should not unnecessarily predispose us to dispute the question in its 
larger and more general bearings. Nor should we be unmindful that 
(as Sir Charles Lyell has aptly suggested) “some mere varieties present 
greater differences, inter se, than do many individuals of distinct species ;” 
for it is a truth of considerable importance, and one which may help us 
out of many an apparent dilemma. . 
But, whatever be the several ranges within which the members of the 
organic creation are free to vary, we are positively certain that, wnless 
the definition of a species, as involving relationship, be more ihan a delu- 
ta: 
limits be fixed, is irreconcilable with the doctrine of specific similitudes. 
Like the ever-shifting curves which the white foam of the untiring tide 
ebb and flow; but they have their 
to, to 
parts, in their general outline they remain steadfast and unaltered, as of 
i i : sti ’d to feel 
“Still changing, yet unchanged ; still, doom 
Seidbadsonaition in perpetual rest. 
ica; by Joun 
5. On the Fresh water Entomostraca of South America ; by 
Lussock, Esq., F.Z.S., (Trans. Ent. 8vo, iii, N.S., Part vi) —Mr. Lubbock 
who has taken up the investigation of the Entomosiraca with great 
7 is, Ania bra- 
from South America, Cypris australis, C. brasiliensis, Daphuu 
siliensis, and Diapleslte Graslinsit They were collected by Charles 
Darwin, Esq. 
SECOND SERIES, VOL, XXII, NO. 65.—SEPT., 1856. 
37 
