INTRODUCTION. 7 
what we have said, it follows, that life can be enjoyed by organized bodies 
only. 
Organization, then, results from a great variety of arrangements, which 
are all conditions of life; and it is easy to conceive, that if its effect be to 
alter either of these conditions, so as to arrest even one of the partial mo- 
tions of which it is composed, the general movement of life must cease. 
Every organized body, independently of the qualities common to its tis- 
sue, has a form peculiar to itself, not merely general and external, but ex- 
tending to the detail of the structure of each of its parts; and it is upon 
this form, which determines the particular direction of each of the partial 
movements that take place in it, that depends the complication of the ge- 
neral movement of its life—it constitutes its species and renders it what it 
is. Each part co-operates in this general movement by a peculiar action, 
and experiences from it particular effects, so that in every being life is a 
whole, resulting from the mutual action and re-action of all its parts. 
Life, then, in general, pre-supposes organization in general, and the life 
proper to each individual being pre-supposes an organization peculiar to 
that being, just as the movement of a clock pre-supposes the clock; and 
accordingly we behold life only in beings that are organized and formed to 
enjoy it, and all the efforts of philosophy have never been able to discover 
matter in the act of organization, neither per se, nor by any external 
cause. In fact, life exercising upon the elements which at every moment 
form part of the living body, and upon those which it attracts to it, an ac- 
tion contrary to that which, without it, would be produced by the usual che- 
mical affinities, it seems impossible that it can be produced by these affini- 
ties, and yet we know of no other power in nature capable of re-uniting 
previously separated molecules. 
The birth of organized beings is, therefore, the greatest mystery of the 
organic economy and of all nature: we see them developed, but never be~ 
ing formed; nay more, all those whose origin we can trace, have at first 
been attached to a body similar in form to their own, but which was deve- 
~ loped before them—in a word, to a parent. So long as the offspring has 
no independent existence, but participates in that of its parent, it is called 
a germ. 
The place to which the germ is attached, and the cause which detaches 
it, and gives it an independent life, vary; but this primitive adhesion to a 
similar being is a rule without exception. ‘The separation of the germ is 
called generation. 
Every organized being reproduces others that are similar to itself, other- 
wise, death being a necessary consequence of life, the species would be- 
come extinct. 
Organized beings have even the faculty of reproducing, in degrees vary- 
