86 On the Fruetification of Seeds. 
among them, which is almost always the case..'This at once 
reuders that trial nugatory. Then it must be recollected that 
niost flowers can be impregnated from pollen of the same species. 
This is another cause of uncertainty. The only true method, 
therefore, is trying those plants that never produce, or will bear 
this mode of management; among whose pistils male plants are 
never found, and that cannot be impregnated from other pollen 
than their own. There are a few of these: Vhe Palms, the 
Pistachio nut, the Fig, and two or three more. These have been 
for years without producing fruit, on the failure of the male 
plant. I had a complete proof of this, which I shall give, as it 
is in vain to repeat Linneus’s excellent trials, which are in every 
botanical book. When I was at Lisbon, in passing to the Caul- 
ders, about half way I came to a viliage, where there were at 
that time many female palm-trees and no male, but in the mid- 
dle of each tree was placed a branch of the male. I inquired 
the-reason. The man told me he had planted many, and chose 
them wrong from ignorance, and for years they had given no 
fruit, as there were then no palms on this side of Lisbon; but 
his children going to Lisbon brought a branch of the male palm, 
and stuck it in the tree, and that tree gave fruit. The next year 
he had therefore performed the same to each, and had always a 
quantity of dates. t 
At Belle Vue I planted a female Juniper ; and it never had 
fruit, though there were many male plants within two miles: but 
it was placed on a remarkably high hill, where the winds blew 
with violence. After many years experiment I wished to try 
a male plant, and placed it near; and I had fruit very soon after, 
within two years I think. As to the Fig, it is the only flower 
that appears to me ¢ruly to be made for the insect to do-the 
office, since both parts are confined in a receptacle which is laid 
open at the proper time. When the insect Cynips enters the 
male Fig, it rolls itself in the pollen, then flies to the female, and 
deposits the powder all round the aperture which nature makes 
at this time in both fruits. * Here at the entrance it inserts its own 
eggs, and leaves the pollen all round the orifice, which is soon 
conveyed to the stigma by means of the juice of the pistils, which 
almost overflow the receptacle with their liquid. 
By what means will the pollen of the Primula veris, thrown 
on the Primula vulgaris, make a Cowslip of it the next year, 
though that flower is so rare in this county of Devon,—and that 
degenerate and return to its original species, if the frial is not 
repeated? Why will the pollen of the Sweet purple Pea, thrown 
on a number of white ones, give seed the next year that will 
bestow a pretty equal number of both colours, and some varie- 
gated? 
