Mr. Knight on the inverted Action 
peculiarity to privation of nutriment, owing to the tubers being 
formed preternaturally early, and thence drawing off that 
portion of the true sap, which in the ordinary course of nature 
is employed in the formation and nutrition of blossoms and 
seeds. 
I therefore planted, in the last spring, some cuttings of a 
very early variety of the potatoe, which had never been 
known to blossom, in garden pots, having heaped the mould 
as high as I could above the level of the pot, and planted the 
portion of the root nearly at the top of it. When the plants had 
grown a few inches high, they were secured to strong sticks, 
which had been fixed erect in the pots for that purpose, and 
the mould was then washed away from the base of their stems 
by a strong current of water. Each plant was now suspended 
in air, and had no communication with the soil in the pots 
except by its fibrous roots, and as these are perfectly distinct 
organs from the runners which generate and feed the tuberous 
roots, I could readily prevent the formation of them. Efforts 
were soon made by every plant to generate runners and 
tuberous roots ; but these were destroyed as soon as they 
became perceptible. An increased luxuriance of growth now 
became visible in every plant, numerous blossoms were 
emitted, and every blossom afforded fruit. 
Conceiving, however, that a small part only of the true 
sap would be expended in the production of blossoms and 
seeds, I was anxious to discover what use nature would make 
of that which remained ; and I therefore took effectual means 
to prevent the formation of tubers on any part of the plants, 
except the extremities of the lateral branches, those being 
the points most distant from the earth, in which the tubers are 
