ig6 Mr. Knight’s Experiments on 
opinion. The principal object I had in view, was to obtain new 
and improved varieties of the apple, to supply the place of those 
which have become diseased and unproductive, by having been 
cultivated beyond the period which nature appears to have as- 
signed to their existence. But, as I foresaw that several years 
must elapse, before the success or failure of this process could pos- 
sibly be ascertained, I wished, in the interval, to see what would 
be its effects on annual plants. Amongst these, none appeared 
so well calculated to answer my purpose as the common pea ; 
not only because I could obtain many varieties of this plant, of 
different forms, sizes, and colours ; but also, because the struc- 
ture of its blossom, by preventing the ingress of insects and 
adventitious farina, has rendered its varieties remarkably per- 
manent. I had a kind growing in my garden, which, having 
been long cultivated in the same soil, had ceased to be produc- 
tive, and did not appear to recover the whole of its former vi- 
gour, when removed to a soil of a somewhat different quality; 
on this, my first experiment, in 1787, was made. Having opened 
a dozen of its immature blossoms, I destroyed the male parts, 
taking great care not to injure the female ones; and, a few 
days afterwards, when the blossoms appeared mature, I intro- 
duced the farina of a very large and luxuriant gray pea into 
one half of the blossoms, leaving the other half as they were. 
The pods of each grew equally well ; but I soon perceived, that 
in those into whose blossoms the farina had not been intro- 
duced, the seeds remained nearly as they were before the blos- 
soms expanded, and in that state they withered. Those in the 
other pods attained maturity, but were not in any sensible de- 
gree different from those afforded by other plants of the same 
variety; owing, I imagine, to the external covering of the seed 
