10 
ADAPTATION A'NB TREATMENT OP COMBEETUM PURPUEEUM. 
is easily reconciled with the principles of culture and conditions now insisted upon, as 
essential to its successful growth in pots, and in favour of which, it may he regarded as a 
most valuable illustration, when it is considered that a simply opposite treatment, by 
permitting the internal temperature of the house, to rise to that intensity during the 
summer, of which the plant is well known to be capable of enduring, would alone prove 
sufficient to a vigour of growth equal to its highest fertility. 
The capability of a plant which is a native of a very hot climate, not only existing under 
such an amazing disparity of temperature, but maintaining an amount of vitality equal 
to that described, can only be accounted for, by a consideration of the physiological 
structure of this, and all similarly organised plants ; in relation to the laws which govern 
the atmosphere around them, and which may be defined as follows -.—Plants are capable of 
resisting cold, and opposite extremes of temperature, in proportion to the small amount of 
fluid matter contained within their organs, and vice versa; and also in proportion to the 
capability which their roots possess, of imbibing nutritive properties in such positions, as 
exclude them from the action of the atmosphere and radiation of heat. 
Those who are acquainted with the habit and structure of the plant now referred to, 
w^ill recognise its remarkable fitness for the position described, especially when it is 
remembered that the plant was placed within a ground-border, and its most important 
root-organs preserved from all the parching and impoverishing influences, to which 
plants in pots would otherwise be exposed ; and consequently it is affirmed on the 
evidence of practical experience, that had the plant been placed under artificial conditions 
of growth, any course of after-treatment, however judicious, would have produced very 
difi'erent results. These views of the instance cited, are strongly corroborated by the fact of 
the earth's greater uniform temperature at any given depth, than on its surface, and from 
which law, in reference to the present subject, it may be inferred, that the nearer the 
conditions of nature, under which the maturity of growth in plants is obtained, the more 
uniform and favourable it will be to fertility, and the less liable to suffer from external 
vicissitudes of temperature, and vice versa. 
Those who seek to attain the highest results of cultivation, should observe the important 
distinction between fetrictly artificial, and natural conditions, (the former in pots, and 
the latter in pits, or ground-borders), involving, as it does, essential points, especially 
with regard to temperature, and upon the observance of which, the successful application 
of general rules more or less depend. For example, in the former, it may be assumed as 
a positive and invariable rule, that a progressively high temperature during the season of 
growth, is essential to plants whose continued fertility depends upon an annually re-accumu- 
lated vigour in their root-organs and leaf-buds ; whilst in the latter (culture in pits or 
borders), high temperature is less essential in proportion as the plants have attained a 
mature size and growth ; because plants under such conditions being preserved from the 
fluctuations of temperature, possess a greater and more uniform degree of vitality through- 
out their orgaiis, which render them more susceptible of growth, and more favourable to 
fertility under lower degrees of top temperature, than in others, whose vigour is annually 
exhausted in pots, by excessive alternations of drought and moisture. 
One of the most important reasons, for attaching a high value to the difference of 
temperature in application to the growth of plants, arises from the consideration, that the 
atmospheric agencies necessary for the production of growth and bloom, separately con- 
sidered, are so far different, as to produce totally opposite results, and thus, equally capable, 
by injudicious apphcation, of being subversive of each other's effects. In other words, the 
amount of heat and moisture contained in the atmosphere which is essential to growth, is 
equally unfavourable for the production of bloom, and vice versa ; hence how valuable is 
that knowledge which is equal to a correct application of both, since each is of equal 
importance where the ultimate object of growth is required, whether of fruit or flowers. 
These considerations suggest the following important truth, — that however low the 
temperature under which plants occasionally mature their bloom, it does not legitimately 
follow, that an equally low temperature is favourable to the continued production of 
growth, requisite for similar results ; it having been shown, that the producing causes are 
opposite in their influence ; and, consequently, as growth, solely considered, is invariably 
antecedent to bloom, it fellows that the efficient cause of the latter is not necessarily an 
equivalent in the production of the former. 
