J80 
SUCCULENT PLANTS. 
ment, owing to their having no definitive period of extension, cannot be taken as 
an index of what they would be in a purely inartificial state. 
Another but much more dubious cause of the impunity with which Cactacese 
suffer extreme drought on the burning plains to which they lend a not very widely 
diffused but permanent verdure, is to be sought in the profusion of their spines, 
and the recently-broached theory that sharp points of this kind assist greatly in 
the precipitation of dew and the conduction of electrical fluid. If it be susceptible 
of proof that the latter, like the nervous fluid in the human body, pervades and 
strengthens vegetable substances, and imparts not only a capacity of exertion, but 
endurance, — and if spiny protuberances undoubtedly attract it,— Cactacese are 
certainly provided with numberless facilities for acquiring its influence. On this 
point we offer no opinion, but wait the accession of greater light. 
Those who are anxious to ascertain the more prominent reasons for the security 
of Cactaceous plants amid agents which would indubitably destroy most classes of 
vegetation, will have learned sufficient from the foregoing statements fully to 
account for their tenacity of life. The thickness or toughness of their outer skin, 
the comparative remoteness of its pores after proper maturation, the scarceness of 
roots, and the sluggishness of sap which the last two causes produce, respectively 
contribute to render their existence in a dry situation, with hardly any affluence of 
water, a matter of neither astonishment nor incertitude. 
We have entered upon the foregoing inquiry because nothing is of greater 
moment in the management of plants than a knowledge of their general constitu- 
tion and habits. Assuming that the physiology of these plants were unknown, 
every cultivator would be justified, from the pulpy nature of their stems, in 
administering immense quantities of water ; whereas, with our present information 
concerning them, we are satisfied that they need less liquid, save for a very short 
portion of the summer, than the most meagre and slender of ornamental exotics. 
And we cannot but entertain the conviction that some culturists are yet ignorant 
of the facts we have recorded ; at least, if their practice may be taken as a fair 
criterion. Watering, in most of the places to which we have access, is conducted 
unremittingly from the beginning to the end of the year ; and while Nature 
suggests that they should be kept doubly dry in our winters, to compensate for 
the excessive aridity in which they are so long maintained in their native plains ; 
the silly notion seems to have gained upon us that plants cannot retain their 
vitality without water, and we sullenly submit to be robbed of flowers, and even 
to lose the plants altogether, by the encroachments of dampness, that this most 
unphilosophical propensity may be gratified. We therefore deem over-watering 
one of the most decided and serious evils in the culture of succulents ; and it is an 
evil, too, the magnitude of which cannot be too forcibly urged ; for of all that we 
can call to mind, there is none so invariably perpetrated, or in the perpetuation of 
which gardeners are so grossly culpable. 
Not to omit any preliminary general intelligence respecting the conditions in 
