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be transferred from the one to the other so as to impregnate the female 
fig, unless there be some artificial perforation as by birds or insects. 
Some naturalists have supposed that there is a kind of gnat produced in 
the male fig which performs this fecundating process. The fig trees of 
some countries, however, are all females and their seeds consequently 
unprolific ; and yet, they have been propagated for many generations 
exclusively by layers and suckers, without any apparent diminution of 
vitality. 
We submit whether these facts, with hundreds of others that might be 
named, tend to establish, beyond the reach of controversy, the alleged 
degradation of species ; the progressive deterioration of higher organiza¬ 
tions into lower, for which the * wearing-out * theorists contend. If it 
be true that the evil lies in the modus colendi , in the propagation by ex¬ 
tension ; then, the argument stands good against every individual plant 
thus cultivated. Nay, the argument is more irapregnably laid against 
those which are not furnished with a double method of propagation than 
against those that are. For nature in supplying the potato with the two 
modes must have intended the one as a substitute for the other only 
when the exigencies or wants of the individual plant, should require it. 
If by being continuously propagated by the tuber for nearly two hundred 
years, it has at length arrived at a point when its existence depends upon 
a new impregnation ; then it demands no more for the purposes of re¬ 
generation after two hundred successive reproductions, than a plant 
propagated by seed only, does after a single reproduction. 
The potato is, in one respect, an annual plant only. Its flowers and 
stems die annually ; the act of reproduction exhausting its vital energies 
so as to limit it to one season of growth. It differs from the herbaceous 
annuals and biennials only in respect to its mode of propagation. Each 
individual plant dies at the end of the first year the same as annual plants 
die; and unless we consider the tuber as a sort of underground stem and 
its eyes as young shoots ; or rather unless we consider the tuber as a kind 
of hybernating plant itself; one that has retired into winter quarters, 
and only comes out in the spring after thermometrically gauging the 
weather, it is to all intents and purposes an annual. But call it peren¬ 
nial and its terminology only applies a lasting throughout the year. Now, 
if we were to apply the same theory of exhaustion ; of wasted vitality 
