January 17, 18S4. ] 
JOURNAL OF HORTICULTURE AND COTTAGE GARDENER. 
41 
majority of the typical forms, the cells being large and mostly filled with 
a clear water-like fluid, but in others with milky mucilaginous or 
slightly acrid juices. There is also usually a quantity of crystals of oxalate 
of lime, which are readily seen if a stem is cut after being dried. Having 
n© leaves the function of respiration must be performed by the stem ; but 
as this has to serve as a reservoir of nutriment generally exposed to a 
burning tropical heat, it is obviously of importance that the evaporation 
very frequently coloured alike, and only distinguishable with great 
difficulty. The colours most abundant are shades of rose, crimson, 
purple, and yellow, some being white and others greenish. Many flowers 
possess a powerful and most pleasing fragrance, but they are usually 
of extremely short duration, some lasting but a few hours during the 
evening or night. The fruit is of a fleshy substance, and in the case of 
several species, such as Cereus speciosissimus and Opuntia vulgaris, it is 
FIG. 7.—THE SUCCULENT HOUSE AT KEW. 
'from the surface should be reduced to a minimum. As a means to this 
end we find that the stomata or breathing pores, which are so abundant 
cn the leaves of most plants inhabiting temperate climates, are in the 
Cacti comparatively few. To this, together with a peculiar structure of 
the walls of the cells forming the superficial layer, is due the remarkable 
heat and drought-enduring character that enables it to live and thrive 
where most other vegetation would perish. 
The flowers differ much in size and colour, but they mostly agree 
n the large number of sepals, petals, and stamens, both the former 
edible, and when well ripened of a very agreeable flavour, somewhat 
resembling that possessed by some fruits of the Gooseberry family, to 
which the Cacti are distantly related. 
DISTRIBUTION. 
North and South America are the principal homes of Cactaceous plants, 
the greatest strength of the order being concentrated in Mexico, which 
contains nearly tbree-fourth3 of the entire number known. Brazil, Peru, 
Chili, Guiana, Colombia, and some other districts in South America also 
