406 TENDENCY OF PLANTS TO REPRODUCE THEMSELVES. 
quite astonishing; and the immense capital required and employed in 
raising vegetables for the London markets, is inconceivable. All their 
proceedings are carried on so systematically,—crop succeeding crop so 
incessantly and properly,—-that not an hour of time is ever lost, or a 
square yard of ground ever, it may be said, seen unoccupied, or use¬ 
lessly idle. Their rotations of cropping are based on the best principles 
fixed by long experience, and in many instances quite distinct from the 
rules of culture pursued in private gardens. Each compartment of their 
ground undergoes a course of cropping; common vegetables alternating 
with fruit-bearing herbs, shrubs, and trees ; that which has for several 
years borne common culinary vegetables, is dressed and laid down for 
two or three years with strawberries, or planted with raspberries, cur¬ 
rants, gooseberries, or with apple, pear, or cherry trees, each of which 
are allowed to stand as long as they are profitable, but no longer, when 
the soil is again broken up, and returned to the production of common 
vegetables. 
On the tendency of Plants to reproduce themselves.— 
It is a general law of nature, obtaining in both the animal and vegetable 
kingdoms, that, in order to perpetuate the species, each individual or 
pair of individuals are so constituted, that by a union of their powers 
respectively progeny is produced. 
It is remarkable, that in both those kingdoms the manner of produc¬ 
tion is similar. The eggs of animals are very similar to the seeds of 
plants; and the bulbs, and tubers, and suckers of plants bear a strong 
resemblance to the viviparous young of animals. Increase by division 
also obtains in both : the division of the polypi is exactly like the pro¬ 
duction and separation of the sporules of fungi and other inferior orders 
of plants. 
But vegetables are endowed with greater powers of reproduction 
than animals. The latter have only one manner of reproduction, from 
which there can be no departure. Oviparous animals cannot bring 
forth young viviparously (except in a few instances among insects), 
nor vice versa . Whereas among plants we find many that can repro¬ 
duce themselves in three different ways, namely, by seeds, by offsets, or 
by suckers ; and what is very remarkable in such cases is, that which¬ 
ever of these take the lead in productiveness, the other two are neutral¬ 
ised or nearly so; and this versatility of character may be made so 
subservient to the purposes of the manager, that he may have whichever 
of the three he may choose. If offsets be wanted from a bulb or tuber, 
or from a fibrous-rooted plant, the flower stem or stems must be cut off ; 
and if seeds be the object, then every new offset or tuber should be dis¬ 
placed as soon as it makes its appearance. 
