from the sea, but the sun. This is their cuticle, 
which, as observed by Sir J. E. Smith, admits ol 
the passage of fluids from within as well as from 
without, but in a due and definite proportion in 
every plant; consequently, it must be porous, and 
the microscope shows what reason would teach us 
to expect, that its pores are different in different 
kinds of plants. In very succulent plants, as Aloes, 
a leaf of which being cut off, will lie for many weeks, 
in the sun without drying entirely, and yet when 
perfectly dry, will become plump again in a few 
hours, if plunged into water , the cuticle must be 
very curiously constructed, so as to admit of ready 
absorption, and yet very tardy perspiration. Such 
plants are accordingly designed to inhabit hot sandy 
countries, where they are long exposed to a burning 
sun, with very rare supplies of rain. 
The rational cultivator will avail himself of this 
knowledge in his treatment of succulent plants, and 
will endeavour to place them under circumstances 
somewhat analogous to those to which they are sub- 
jected by nature herself. Seeing, then, the deficient 
powers of perspiration under which these plants 
exist, he will, of course, expose them to a dry atmos- 
phere, and thus assist them in expelling any super- 
abundance of fluids, taken up by the roots. If 
in winter, when the action of the cuticle is still 
more languid than in summer, the roots be sup- 
plied with much water, decay will be the result. 
During winter many of these plants succeed best by 
being entirely deprived of water, except that carried 
by the atmosphere, which is found to be sufficient, 
even in a sitting room with constant fire. 
