50 Vegetable Organography and Physiology. | 
vances have been made in the study of vegetable anatomy and 
physiology, by the labors of De Candolle, Dutrochet, Lindley, 
and, more recently, the interesting inquiries of Carpenter, as to 
lead to the belief, that the day is not distant when the naturalist 
will discover, from the study of vegetable life, an explanation of 
the cause of many of those phenomena which have, hitherto, 
baffled the inquiries of the animal physiologist. Already the re- 
mark made by Cuvier, on the various forms and vital functions of 
animals, may, with equal fitness be applied to those of the vege- 
table kingdom ; that they “are so many kinds of experiments 
ready prepared by nature, who adds to, or deducts from each of 
them, different parts, just as we might wish to do in our own ~ 
laboratories, showing us herself, at the same time, their various re- 
sults.” This is, indeed, the only true method of studying phys- — 
iology: to listen to the language of nature, as she spontaneously _ 
reveals her secrets, is far preferable to the inquisitorial method * +! 
extracting them from her, by cruel experiments. + | 
ut before we undertake a description of the organs of — 
or of their functions, or attempt to trace the analogy which ex- 
ists between the two kingdoms, vegetable and animal, it will be 
necessary to make a few brief inquiries into the nature of the 
primary tissues, which enter into the structure of the vegetable 
formations. 
The primary tissues, or elementary organs of all plants, ee 
three in number; the cellular tissue, the woody fibre, and the vas-_ 
cular tissue, or spiral vessels. To these is sometimes added 
another tissue, denominated ducts. Late inquiries, however, have — 
shown these ducts to be a variety in the form of the spiral vessels, 
and to be identified with them. 
The cellular tissue enters into the composition of all vegetables. 
It is composed of minute, transparent vesicles, or cells, the sides 
of which are adherent to each other. These vesicles are exceed- 
ingly minute ; varying in size, in different plants, from the 30th _ 
to the 1000th part of an inch. They generally contain an elabo- 
rated fluid, which circulates freely, in all directions, through the 
vegetable membrane that forms the sides of these cells. But the 
ium by which this circulation is earried on, has, for a long © 
time, engaged the inquiries of vegetable physiologists. ‘The cells 
do not communicate by any appreciable pores or fissures. Notli- 
ing of the kind has ever yet been discovered, although they havé 
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