REMARKS ON VEGETABLE GROWTH, ETC, 
12.9 
and flower-buds, the flowers and foliage of the following year are 
plainly discernible ; and if it were practicable to divide such a 
plant as the Agave Americana, ten years before it would naturally 
flower in this country, there can be no doubt but that the embryo 
flower would be visible in the centre. 
This idea presupposes that all the parts of a vegetable have 
rudimental existence, and that they are developed in the order of 
their position in the system. This, perhaps, is the oldest and most 
generally-received opinion relative to this branch of botanical 
knowledge. But a belief of it does not satisfy our mind respecting 
the question at the beginning of this communication ; because by 
reference thereto we cannot explain why one tree is fruitful, and 
another barren. 
Much has been written and said on the question ; and it was set 
at rest by one party of philosophers, who believed that the elabo¬ 
rated sap was convertible into all the different organs of the plant, 
and particularly into those of flowers and fruit. And in order to 
arrest this same elaborated sap in the branches, every plan of 
reversing, or ringing, or strangulating them, is advised to prevent 
it sinking to the roots. Of course it is believed that neither 
flowers nor fruit can be generated or formed in the buds of a plant 
unless perfect sap is present; and the greater the store the more 
numerous are the flowers and fruit. This fruit-producing sap is 
compounded by the agency of the leaves ; so that without leaves 
there can be no elaborated sap ; and without this last, there can 
be neither flowers nor fruit. So that the presence or absence of 
fruit is easily accounted for by assuming, that the perfect sap is 
more or less abundant. This theory was first propounded by the 
late T. A. Knight, Esq., President of the Horticultural Society of 
London, and lias been very generally adopted. 
But the question has been answered in another way : it is first 
of all presumed, that the leaves, flowers, and fruit are all of the 
same substance, and that they are either one or the other according 
as the growth of the plant is more or less luxuriant. When plants 
are young, or even in old age, if in a vigorous habit of growth, 
strong shoots and leaves only are produced ; but if by any means 
the growth becomes languid, and the shoots stunted, whether by 
art or accident, instead of the powers of the plant being exhausted 
in the production of barren shoots and leaves, these last are trans¬ 
formed into flowers and fruit. Thus, by metamorphosis, the leaves 
VOL. IT. NO. VI. 
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