xcg lOn the Fecundation of VegetalCes. 



VIII. 



An Account of fome Experiments on tlie Fecundation of Vigetables. By Thomas 



Andrew Knight, E.fq.* 



X. HE refult of fome cxpeviments -which 1 have amufcd myfelf in mal:ing on Plants, 

 appearing to me to be interefting to the naturalifls by proving the exiftence of fuperfoe- 

 tHtion in the vegetable world, and being likely to conduce to fome improvements in 

 Agriculture I have taken the liberty to communicate them to you. 



The breeders of animals have very long entertained an opinion that confiderable advant- 

 J^ges are obtained by breeding from males and females not related to each other. Thougk 

 this cipirrion has lately been controverted, the numbers of its oppofcrs are gradually 

 diminifhed ; and I can fpcak from my own obfervation and experience that animals 

 degenerate in fize at lead on the fame paftiire and in other refpefls under the fame 

 management when this procefs of crofTmg the breed is neglefted. 



The clofe analogy between the animal and vegetable world and the fexual fyflem 

 equally pervading both, induced me to fuppofc that fimilar means might be produclive of 

 fimilar efFefts in each ; and the event, has, I think, fully juftified this opinion. The 

 principal objeft I had in view was, to obtain new and improved varieties of the apple, 

 to fupply the place of thofe which have become difeafed and unproduftive by having 

 been cultivated beyond the period which nature appears to have affigned to their exift- 

 ence. But as I forefaw that feveral years mud elapfe before the fuccefs or failure of 

 the procefs could poffibJy be afcertained, I wifhed in fhe interval to fee what would be 

 its effefts on annual plants. Among thefe none appeared fo well calculated to anfwer 

 my purpofc as the common pea ; not only becaufe I could obtain many varieties of this 

 plant of different forms, fizes, and colours ; but alfo becaufe the ftrntture of its bloffom 

 by preventing the ingrefs of infedb and adventitious farina has rendered its varieties 

 remarkably permanent. I had a kind growing in my garden which having been long 

 cultivated in the fame foil md ceafed to be produftive, and did not appear to recover 

 the whole of its former vigor when removed to a foil of a fomewliat different quality. 

 On this, my flrfl experiment in 1787, was made. Having opened A dozen of its im- 

 mature bio (Toms, I deflroyed the male parts, taking great care not to injure the female 

 Ones ; and a lew days afterwards, when the bloffoms appeared mature, I introduced the 

 farina of a very large and luxuriant grey pea into one half of the bloffoins, leaving the 

 other half as they were. The pods of each grew equally well ; but I foon perceived 



* Philof. TranTaflions, 17991 Pan II. pi 195. 



