Species

126 Species

Some of Lamarck’s transformist views on species had been championed by

Etienne Geoffroy Saint-Hilaire (1772–1844), Isidore’s father, although he did not

make much of the rank of species as such, preferring to focus instead upon the “unity

of plan”—relations (“analogies,” or as we now call them, homologies) between dif-

ferent classes of organisms, in keeping with his transcendentalist views. His main

statement about species was that they were not fixed:

The species is not fixed and does not reappear in its forms, except for the reason that

the conditional state of its ambient medium is maintained; for, according to the bear-

ing and under the influence of the latter, there are scarcely any changes which are not

possible with respect to it.^54

Geoffroy’s views were popularized by Chambers’ Vestiges of the Natural History

of Creation.^55

(^54) Translated in Le Guyader 2004, 228.
(^55) Chambers 1844. Chambers wrote of species:
(^) species, the subdivision where intermarriage or breeding is usually considered as natural to ani-
mals, and where a resemblance of offspring to parents is generally persevered in. The dog, for ins-
tance, is a species, because all dogs can breed together, and the progeny partakes of the appearances
of the parents. The human race is held as a species, primarily for the same reasons. [page 263]
Vers. Infusoires.
Polypes.
Radiaires.
Insectes.
Arachnides.
Annelides. Crustacés.
Cirrhipèdes.
Mollusques.
Poissons.
Reptiles.
Oiseaux.
Monotrèmes.
M. Amphibies.
M. Cétacés.
M. Ongulés.
M. Onguiculés.
TABLEAU
Servant à montrer l’ origine des différens
animaux
A
FIGURE 4.1 Lamarck’s “tree.” A. Lamarck’s original table. Note that he uses sparse dots to
indicate affinities. (Continued)