54 Prof. Owen on Life and Species. 
cn ie operation of a developmental force, or ‘nisus forma- 
“Haller maintained the principle of ‘ evolution,’ Buffon that of 
see both principle at work, s tbgethne with a hide ’ However, 
as he limited the ‘ pre-existing entities’ to ‘the materia vite 
universalis’ and the ‘absorbent faculty,’ he would now be 
classed with the ‘epigenesists.’ For, he reckoned among the 
parts newly built up, not evolved, ‘ the brain and heart, with 
their appendages, the nerves and ‘vessels, and so on of all the 
other parts of the body which we do not find at first’* His 
third principle is merely a modification of = Ne Viz: 
‘change in form and action of pre-existing parts.’ 
At the present day the question may seem hardly worth the 
paper on which it isreferred to.| Nevertheless, ‘ pre-existence 
of germs’ and ‘ evolution’ are — inseparable from the 
idea of the origin “of species by primary miraculously created 
individuals. Cuvier, therefore, satiated both, as firmly as 
did Haller.{ It is, perhaps, one of the most remarkable in- 
to constitute the ‘circulus vasculosus’ of the vitellicle, Cuvier 
opposes the following remark :—‘ Mais il faut nécessairement 
admettre qu’il y avait une pré-existence de quelques chemins 
pour les pointes rouges ; car en virtue de quelle force la figure 
veineuse serait-elle “toujours composée des mémes vaisscaux 
ayant la méme direction ? esas ces vaisseaux abouti- 
raient-ils toujours au méme point pour former un coeur ? Tous 
ces nénoménes ots sont intelligibles qu’autant qu’on admet 
quelque y , 
Haller, i had mi made some good observations onembryonal [| 
development, confessed that there was a stage in that of the | 
chick in which the « intestinal canal was not sible : ? he would f 
* xX. vol. v, p. xiv. 
The 
t encasement or inboxing c emboitement’) of germs was deemed, a cen- 
tury or more to receive sear evolution of buds and other 
of plants, and from Sw: n’s in sow is, not only of the 
parts which afterwards form ho butterfly, ‘ ne, &c., but also of the 
as wings, a 
eggs which were to be laid in n that t phase of life. cee drew ‘an inference in 
favor of the same 
= <i pp. 7, 35) might be impregnated by a single Peers (See, pea a 
Sexy’. = wis , Pls. 
| coovr’. cco”, pesmi p. 236. 
