PHYSIOLOGY. $29 
spring is obtained from these two, which in form 
and properties resembles both father and mother. 
§ 294. | 
But there have been philosophers, as well in for- 
mer as at the present times, who in plants have 
altogether denied the existence of sexes. Smiellie 
seems to favour this opinion, because he repeat- 
ed an experiment of Spallanzani’s, with a female 
plant of hemp, which he kept remote from all 
male plants, and notwithstanding obtained, though 
in a small quantity, perfect seeds, and hence he de- 
duces his arguments. But indeed such experiments 
are too difficult to be free from error, and who can 
assert, that he has not, even with the greatest atten- 
tion, been deceived? Spallanzani placed his female 
plant ina room, to which no insects could get, and, 
for the greater security, likewise covered it. But 
could he, before the first flower appeared, distinctly 
enough distinguish the female plant of the hemp? 
And could not avery small, minute insect escape 
his eyes, and effect a fecundation? Besides, do we 
not find on female plants sometimes a few male 
flowers, which perhaps was here the case? The 
few seeds which he got, prove, that a few single 
parts were necessarily fecundated. But even sup- 
posing that in hemp the female plant produces ripe 
seeds without fecundation, can we draw any just 
conclusion from this single plant to any other vege- 
table? We have in the animal kingdom an instance 
in the Aphis, am insect which, without the aid of a 
male, propagates itself till autumn. But who would, 
from 
