154 
VEGETABLE PHYSIOLOGY. 
The identity of this vital member is, Mr. Main says, visible and palpable during 
summer in the form of a white belt: it is the swelling cambium, that ultimately is 
divided into two distinct layers ; between which, " an almost imperceptible mem- 
brane or coating of gelatinous matter" is interposed. This is the vital envelope 
from which " the new growths of wood and liber of the next and all succeeding 
years will be produced." — (See Main's Illustrations of Vegetable Physiology.) 
If the reader appreciate these few detached and abbreviated extracts from a 
work which ought to be deeply studied, he will be interested in comparing them 
with the facts which will now be adduced in proof that organization may be 
effected in prepared nutritive fluids. 
We are jealous of analogies between animal and vegetable bodies; they 
mystify and lead to fanciful conclusions : but there is one point wherein a fair 
analogy may be traced, and that is, that the vitality of the nutritive fluids of both 
the cambium or vital indusium is the pabulum of vegetable organization, just as the 
blood is the support of animal life and the cause of growth and increase ; and both 
are endowed with life : let the annexed truths speak for themselves. 
" If a living egg be exposed to a degree of heat equal to the temperature at 
which the egg is maintained during incubation, certain motions or actions are 
observed spontaneously to arise in it, which terminate in the development of a 
chick. An analogous process takes place in the blood : if it be effused from its 
vessels in the living body, either upon the surfaces of organs or into cavities, it 
solidifies without losing its vitality. This is not the same process as the coagulation 
of blood out of the body ; it is a vital process indispensable to the action, and 
completely under the control of the vital principle. If blood thus solidified within 
the body be examined sometime after it has changed from the fluid to the solid 
state, the solid is found to abound with blood-vessels. Some of these vessels can 
be distinctly traced passing from the surrounding living parts into the mass of the 
solidified blood : with others of these vessels no communication whatever can be 
traced. A clot of blood surrounded by living parts becomes organized — no dead 
substance thus surrounded by living parts becomes organized ; the inference is that 
the blood itself is alive." 
But blood coagulates when drawn from the living body, and separates into two 
distinct portions. " In three minutes and a half the change is sufficiently advanced 
to be manifest to the eye ; in seven minutes the fluid is separated from the solid 
portion, while the change progressively advances, until, in the space of from twelve 
to twenty minutes, the separation may be said to be complete. 
" The nature of this curious process is imperfectly understood ; it is a process 
sui generis, there being no other with which we are acquainted perfectly ana- 
logous to it. It is really a process of death : it is the mode in which blood dies ! " 
(See the able article on Blood, in the Penny Cyclopaedia ; the author is unknown 
to us.) 
Analogy exists, therefore, between the animal blood and thai fluid which Mr. 
