INTRODUCTORY LECTURES. 729 
whose loss science and letters will long mourn — I mean the im- 
mortal Cuvier. 
“ Anatomy (said he) is not that uninteresting, worthless 
kind of geography of the animal body which describes the or- 
gans, their form, and their situation ; there is something more in 
their economy than the fibres and the vessels — the material me- 
chanical instruments of existence. These organs must all be 
view r ed in action, and executing all the various functions which 
concur to fill up the mystery of life. How can we arrive at this 
important end if we bound our studies to one animal alone I It 
is necessary that we should, in some sort, trace the principle of 
life from the animals who have received but a feeble portion of 
it, and whom only a shade scarcely perceptible separates from 
the inanimate kingdom, to the more perfect beings — to those who 
possess the principle of life in its entire development, and all 
whose faculties attest their high origin. It is thus that physio- 
logy, like every other science, can be founded only on a full col- 
lection of facts. One single exception may destroy the whole sys- 
tem — one single anatomical fact may reverse a whole cloud of 
physiological hypotheses. 
“ Medicine, in order to accomplish the purpose it has marked 
out for itself, must embrace the study of all organized beings. 
“ One admirable law of simplicity presides over the organs, so 
numerous and so various, which constitute the animal frame. 
Around the principal organ of one function we see other acces- 
sory organs forming themselves into groups, all displaying one 
invariable affinity — one striking analogy. In one place, an im- 
portant organ compensates for another that is endowed with fee- 
ble power. Anomalies are only so in appearance ; and even 
monstrosities, which are often called the freaks of Nature, are all 
consistent with that grand law, — the unity of composition in an 
organic being. 
“ Unity and variety ; this is the motto of Nature. She aban- 
dons herself to all her fecundity of invention, and seems to play 
with the accessory forms, while, always faithful to her principle 
of unity in passing from one class to another by an almost in- 
sensible gradation, she seems to lavish organs which no longer 
have any function to fulfil : such are the vestiges of feet in ani- 
mals that are destined to crawd, and such, also, are the imperfect 
digits in the solipede, which demonstrate so beautifully the law 
of compensation. 
“ These laws, so simple and so harmonious, had not escaped 
the profound observation of Aristotle ; but their systematic de- 
velopment was the work and the glory of modern naturalists, — 
Cuvier, Geoffroi, and Deserres. 
5 D 
VOL. XIV. 
