Short-leaved trees should never be selected ; for 
these approach nearer to the original standard: 
whereas the other qualities indicate the influence 
of cultivation. 
In the general selection of seeds, it would appear 
that those arising from the most highly- cultivated 
varieties of plants, are such as give the most 
vigorous produce ; but it is necessary from time 
to time to change, and, as it were, to cross the 
breed. 
By applying the pollen, or dust of the stamina 
from one variety to the pistil of another of the 
same species, a new variety may be easily pro- 
duced ; and Mr. Knight’s experiments seem to 
warrant the idea, that great advantages may be 
derived from this method of propagation. 
Mr. Knight’s large peas, produced by crossing 
two varieties, are celebrated amongst horticul- 
turists, and will, I hope, soon be cultivated by 
farmers. 
I have seen several of his crossed apples, which 
promise to rival the best of those which are 
gradually dying away in the cyder countries. 
And his experiments on the crossing of wheat, 
which is very easily effected, merely by sowing 
the different kinds together, lead to a result which 
is of considerable importance. He says,, in the 
Philosophical Transactions for 1799, “ In the years 
1795 and 1796, when almost the whole crop of 
corn in the island was blighted, the varieties 
obtained by crossing alone escaped, though sown 
in several soils, and in very different situations.” 
The processes of gardening for increasing the 
