402 
all the tadpole stages of metamorphosis while still in the egg. 
All these stages have been observed by M. Baray ; and whoever 
is familiar with the evolution of the ordinary tadpole before it 
quits the egg, will see that M. Baray has observed only a modi- 
fied form of the well-known process. The Guadeloupe frog is 
born as a frog, not as a tadpole ; and this, paradoxical as it may 
seem to some naturalists who cannot dismiss traditional concep- 
tions, is even less remarkable than the case of the Sa/amandra 
atra, because it is only an extension of the period of incubation, 
whereas with the salamander it is the substitution of viviparity 
for oviparity. How the presence of water leads to an accelera- 
tion of the birth, or the absence of water leads to its retarda- 
tion, is an interesting point for investigation ; whether retarded 
or accelerated, the finally-acquired structure is the same. 
The Priory, March 22 GroRGE Henry LEWEs 
Anticipations of Natural Philosophy, 
MAUPERTUIS 
Havin lately had occasion to examine the works of Mau- 
pertuis I, like Prof. Jevons, was struck by meeting with antici- 
patory glimpses of the modern theory of Natural Selection. The 
passage, given almost word for word by Lord Bolingbroke in the 
quotation made by Prof. Jevons, occurs somewhat incidentally 
in two parts of Maupertuis’ writings ; in the memoir alluded to 
(*‘Les Loix du Mouvement et du Repos, deduites d’un principe 
métaphysique”) ; and in the ‘‘Essay de Cosmologie,” into 
which the memoir-was expanded five years later (1751). In both 
these works Maupertuis is chiefly concerned with establishing 
his well-known metaphysico-mechanical principle of ‘‘ The Least 
Action ” (‘‘La moindre Quantité d’Action”) ; and with deducing 
therefrom proof of the existence of God. But the doctrine of 
«© The Survival of the Fittest” is more clearly discernible, and 
more than incidentally referred to, in his small physiological 
treatise, ‘‘ Venus physique” (Euvres, tome ii. ed. 1756). The 
whole of this work is not wanting in interest, but as bearing 
specially on the subject in question, I would mention the third, 
fifth, and last chapters of the second part. Chapter III. is en- 
titled ‘‘ Production de nouvelles especes.” In it the most pro- 
nounced passage is perhaps the following: ‘Mais la sage 
Nature, par le dégoiit qu'elle a inspiré pour ces defauts, n’a pas 
voulu qu’ils se perpetuassent ; chaque pére, chaque mére fait de 
son mieux pour les éteindre ; les beautés sont plus siirement 
héréditaires ; la taille, et la jambe, que nous admirons, sont 
Vouvrage de plusieurs générations, ot l’on s’est appliqué a les 
former.”’ Chapter V., called an ‘‘ Essay d’explication des 
phénoménes précédents,” is an attempt to explain the physio- 
logical processes at work in the preservation of the best types, 
and in the production of new forms. On the efficacy of these 
processes the author says: ‘‘ L’expérience pourroit, peut-étre, 
éclaircir ce point ; si l’on essayoit pendant longtemps de mutiler 
quelques animaux de génération en generation, peut-¢tre verroit- 
on les parties rétranchées, diminuer peu a peu; peut-étre 
verroit-on les 4 la fin s’anéantir.” The last chapter contains a 
summary of the whole work, and a number of “ Doutes et Ques- 
tions,” propounded by the author. In one of these he asks, 
“ Cet instinct des animaux, qui leur fait rechercher ce qui leur 
convient, et fuir ce qui leur nuit, n’appartient-il point aux plus 
petites parties dont l’animal est formé?” In another question 
Maupertuis puts forward a bold hypothesis as to the influence 
which the decomposed material of the dead animal organism 
might exercise upon plants, and through them upon the structure 
and character of the living organism. a 
In his Systéme de la Nature also (Ciuvres, tom. ii. ed. 1756), 
Maupertuis combats the special creation theory of the origin of 
species, and advocates a doctrine, which may be called Natural 
Selection, the selective principle being placed in the ultimate 
elements of both organic and inorganic substances, of which 
elements ‘‘la perception est une propriété essentielle,” and which 
‘‘doués d’intelligence s’arrangent et s’unissent pour remplir les 
vues du Créateur.” f 
Such are a few of the glimpses to be met with in the French 
philosopher, of the modern doctrine of Darwin and Spencer. 
Similar ones may not improbably be found elsewhere, but such 
“ resultless tendencies,” as the course of events has proved them 
to be, can in no degree detract from the merit and originality of 
those who have made of Natural Selection a well-substantiated 
and homogeneous theory. W. H. BREWER 
Grace’s Road, Camberwell, March ro 
NATURE 
[Mar. 27, 1873 
EMPEDOCLES ~ 
On reading Prof. W. Stanley Jevons’ interesting letter in 
this week’s NATURE, I referred to my note-book, and found the 
following quotation, under the title of ‘‘ Natural Selection,” 
which shows that the opinion of Maupertuis is at least as old as 
Empedocles.—‘‘ Cette derniere opinion sert 4 expliquer les idées 
d’Empeédocle sur la production des animaux par des causes acci- 
dentelles. L’attraction et la répulsion des ¢lémens donnérent 
naissance dans les commencemens et par le seul effet du hasard, 
a des tétes sans cou, a des jambes sans corps, 4 des animaux 
moitié bceufs et moitié hommes, en un mot, a une foule de 
monstrés semblances. Parmi tous ces étres, les uns étaient con- 
struits de maniére qu’ils semblaient étres doués de l’'intelligence : 
ceux-la conservérent Ja vie, et propagérent leur espéce, mais 
ceux auxquels l’organe de la vie manquait, retombérent dans le 
chaos, d’ou ils étaient'sortis.” (“Histoire de la Medécine,” par 
Kurt Sprengel, vol. i. p. 249.) Sprengel gives the following 
references :—Aristotle, Physic. Lib. ii., c. 4, p. 465., c. 8, p. 470. 
Owing to my distance from a public library I have not hitherto 
had an opportanity of referring to Aristotle ; but as Prof. Jevons 
is more favourably circumstanced, I hope he will consult the 
original, and if he finds anything which throws further light upon 
this interesting question, that he will report it to your readers. 
Although, as Prof. Jevons remarks, the introduction of the notion 
of chance is erroneous, the speculation shows how thoroughly the 
Greek Atomists had banished from their explanations of pheno- 
mena all reference to first and final causes, anticipating in this 
respect the modern conception of science. I cannot deny myself 
the pleasure of quoting the weighty judgment of Bacon upon 
this point :--‘‘ And therefore the natural philosophies of De- 
mocritus and others,” says Bacon, ‘‘ who allow no God or mind 
in the frame of things, but attribute the structure of the universe 
to infinite essays and trials of nature, or what they call fate or 
fortune, and assigned the causes of particular things to the ne- 
cessity of matter without any intermixture of final causes, seem, 
so far as we can judge from the remains of their philosophy, 
much more solid, and to have gone deeper into nature, with 
regard to physical causes, than the philosophy of Aristotle or 
Plato; and this only because they never meddled with final 
causes, which the others were perpetually inculcating.” (Ad- 
vancement of Learning, Book iii. chap. iv.) 
Waterfoot, March 8 James Ross 
ARISTOTLE 
Ir is interesting, as Mr. Jevons says, to observe such traces as 
are to be found in history of theories more or less anticipating 
the principle of natural selection. But if the instance he cites 
from Maupertuis fairly represents the last century in this matter, 
it is chiefly of interest as showing what a little way it is possible 
to travel on certain roads in twenty-two centuries : for Aristotle 
discusses the same theory in his ‘‘ Physics” (ii. 8), and appears to 
attribute it to Empedocles. ‘‘It may be a question,” he says, 
‘* whether physiological@effects which seem to be due to final 
causes are not really accidental. An organism survived, we 
may suppose, if it happened to be asa whole constituted in a 
suitable manner ; that is, ina manner in which it would have 
been constituted by design ; organisms otherwise constituted 
perished and perish still, like the Bouyer dvipémrpwpa of Em- 
pedocles.” Now, except that his monsters are certainly not 
quite so monstrous, I do not see that the ‘‘Flattener of the 
Earth” gets beyond that. At any rate he lags behind Lucre- . 
tius, who adopts the same theory of ‘‘ discriminative destruc- 
tion” (v. 837-877), but applies it, as Mr. Munro points out (on 
line $55), not merely to monsters but to ‘‘ regularly organised 
creatures,” either not so gifted as to protect themselves or not 
so valuable as to be protected by man. 
This is, as far as it goes, a theory of natural selection. It is 
a theory of the survival of the fit, absolutely; but not being 
a theory of the preponderant survival of the fitter, and not 
taking adequate account of inheritance, it is not a theory 
of evolution. Indeed, though Lucretius recognised a constant 
change in the conditioning circumstances, and therefore in the 
organisms conditioned (828-836), it was to account for the 
stability of species that he called in natural selection and not to 
give a clue to the laws of their variation. That is the direction 
in which there must have been most room for progress ; and 
traces of such progress may be to be found. Has Mr. Jevons 
tried Gassendi ? C. J. Monro 
Hadley, Middlesex 
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