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VEGETABLE PHYSIOLOGY. 
At this point, a very momentous inquiry suggests itself : it is one which the 
human faculties may never be permitted to determine ; yet it is perfectly legitimate, 
and must conduce to admiration, if not to actual discovery. 
Every vegetable being may be referred ultimately to a seed. Does this seed — 
this embryo of a mass of perfected organization — comprise within itself all the 
rudiments of every future development, or not ? 
Here we must take a retrospective view of a work which was published some 
years since, wherein this great question was embodied into an hypothesis, that 
merited far more consideration than it appears to have received. We allude to 
Mr. James Main's Treatise on Vegetable Physiology ; a book not in our possession. 
But fortunately we possess an original letter by the respectable author, from which 
some extracts will here be given, that, we hope, may rivet the attention of many who 
are not under trammels to received authority, however it may occupy " high places." 
Mr. Main assumes, as his basis, the fact which all analogy bears out ; that a 
being is originally perfect in all its parts, and that development and nutrition are 
not in any way identical with a production of new parts. Thus " vegetables 
have an organic frame, containing specific qualities : the former is rudimental ; 
mutable in texture, and expansible under the action of air, heat, light, and water : 
the latter are accretive, in consequence of accessions of vegetable food received from 
the earth and atmosphere. As the frame is extended or expanded, additional food 
is required to fill up and distend the swelling vessels, whereby the whole is enlarged 
in bulk and weight ; this process being continued till the plant arrives at maturity, 
if an annual, or for ever if a perennial. Now, I hold it questionable whether any 
of the food goes to generate organization ! That it fills, distends, supports, and is 
in fact in connexion with the inherent qualities of the plant, — the cause of its 
growth or amplification, is perfectly obvious : but, that fluids, whether aqueous or 
gaseous, however gross, can be changed into organic structure, or even into a single 
cell of that structure, is beyond the powers of my comprehension. 
" I admit that my ideas pre-suppose that the oak once reposed in the acorn : but 
how much more rational and easy of belief is even this notion, than that it came 
into existence without a rudiment or nucleus of organization ! " 
Mr. Main then adverts to his theory of a vital membrane, which he termed, 
subsequently, Indusium ; and views it as the organ which develops annually the 
new layer of alburnum and liber. The prepared, and fully elaborated sap, called 
Cambium, had been considered as a substance capable of becoming organized under 
the stimulus of the vital principle ; and its situation between the new yearly layers 
warranted the assumption with those who could believe that new vital parts were 
bond fide produced. 
But, observes. Mr. Main— " Organization must exist before any expansion can 
take place ; and I must still doubt whether vegetable organs can originate in any 
combination of nutritive elements." He adds, — " There is a distinct member 
situated between the liber and alburnum, so that if waxed paper be placed within 
