106 
THE PERIODICAL REPOSE OF PLANTS. 
SO, will not find a correct solution of this question by referring to tlie capacities of 
any kinds of plants, but in the variation of seasons peculiar to each district over 
w^hich those plants are scattered. 
The opinion that continued excitation vreakens and enervates the energies of the 
vegetable tribes, must be viewed in precisely the same connexion as that to which 
we have just alluded. In temperate climes, vegetation is dormant during the 
winter season, because neither heat nor light is sufficiently intense and durable to 
maintain vital action. Tropical regions, on the other hand, preclude unvarying 
verdure, since moisture is almost if not entirely evaporated at certain periods of 
the year. The winters of some countries (Great Britain for instance) are supposed 
to be necessary to plants ; because they imbibe at this season a quantity of liquid 
food, wherewith to enable them to repair the effects of anterior exertion, and furnish 
means for their future development. Tlie supply of fluids thus obtained is not, 
however, circulated through the entire substance of plants till the return of 
vernal suns and increased temperature ; and as heat alone can render them capable 
of appropriating those fluids, by the prompt application of moisture when necessary, 
no scarcity can ever be experienced : so that the store received during their 
torpidity is by no means essential, or even useful, to the succeeding progress of 
vegetation. 
Of the analogy between plants and animals in this particular, a very few observa- 
tions will suffice to show that the sleep of the higher orders of the latter is of a totally 
difi*erent nature to the repose of plants ; while those instances of periodical dormancy 
which occur in the lower classes of animals, may be distinctly traced to the same 
cause as is here assigned for that of vegetation generally. Animals sleep, — not to 
enable them to grow with greater rapidity and vigour, but to furnish them with a 
renewed capacity for the active exertion of their locomotive powers. Plants, on 
the contrary, not having any such functions to exercise, have all their energies con- 
centrated in the growing process. So long therefore as they can absorb a sufficient 
quantity of nutriment, and at the same time be subjected to the elements which 
will induce them to appropriate and as it were digest it, they need no such 
suspension of their faculties. 
These observations must not be misunderstood as implying the unimportance of 
a periodical cessation of growth. We hold it to be an indispensable feature in the 
cultivation of all plants ; but previously to adopting any particular system of treat- 
ment, we deem it necessary that its applicability and suitableness should be 
distinctly and clearly understood. Some cultivators of Orchidace^e, being deeply 
impressed with the propriety of afi'ording them a season of repose, and not knowing 
that this occurs in their native localities on account of the peculiarities of the climate, 
commit great and dangerous errors. Thus, we have seen many of these plants 
placed in a dry cool house for repose during the summer, and removed to a humid 
heat towards the approach of winter, because they are inert in the hot and dry 
season in their natural state. By this practice, their functions are forced into action 
