508 PHILOSOPHICAL TRANSACTIONS. [ANNO 1790. 



plants in which it has placed the male and female parts within the same empalement. 

 It is often scattered by an elastic exertion of the filaments which support it, on the 

 first opening of the blossom ; and its excessive lightness renders it capable of being 

 carried to a great distance by the wind. Its position within the blossom, is gene- 

 rally well adapted to place it on the bodies of insects; and the villous coat of the 

 numerous family of bees is not less well calculated to carry it. I have frequently 

 observed, with great pleasure, the dispersion of the farina of some of the grasses, 

 when the sun had just risen in a dewy morning. It seemed to be impelled from 

 the plant with considerable force; and, being blue, was easily visible, and very 

 strongly resembled, in appearance, the explosion of a grain of gunpowder. An 

 examination of the structure of the blossoms of many plants, will immediately 

 point out, that nature has something more in view, than that its own proper males 

 should fecundate each blossom ; for the means it employs are always those best 

 calculated to answer the intended purpose. But the farina is often so placed, that 

 it can never reach the summit of the pointal, unless by adventitious means; and 

 many trials have convinced me that it has no action on any other part of it. In 

 promoting this sexual intercourse between neighbouring plants of the same species, 

 nature appears to have an important purpose in view; for, independent of its stimu- 

 lative power, this intercourse certainly tends to confine within more narrow limits, 

 those variations which accidental richness or poverty of soil usually produces. It 

 may be objected, by those who admit the existence of vegetable mules, that, under 

 this extensive intercourse, these must have been more numerous; but my total 

 want of success, in many endeavours, to produce a single mule plant, makes me 

 much disposed to believe that hybrid plants have been mistaken for mules; and to 

 doubt, with all the deference I feel for the opinions of Linnaeus and his illustrious 

 followers, whether nature ever did, or ever will, permit the production of such a 

 monster. The existence of numerous mules in the animal world, between kindred 

 species, is allowed; but nature has here guarded against their production, by im- 

 pelling every animal to seek its proper mate; and among the feathered tribe, when, 

 from perversion of appetite, sexual intercourse takes place between those of distinct 

 genera,* it has, in some instances at least, rendered the death of the female the 

 inevitable consequence. But in the vegetable world there is not any thing to direct 

 the male to its proper female: its farina is carried, by winds and insects, to plants 

 of every different genus and species ; and it therefore appears to me, as vegetable 

 mules certainly are not common, that nature has not permitted them to exist at all. 

 I cannot dismiss this subject, without expressing my regret, that those who have 

 made the science of botany their study, should have considered the improvement 

 of those vegetables which, in their cultivated state, afford the largest portion of 

 subsistence to mankind and other animals, as little connected , with the object of 

 their pursuit. Hence it has happened, that while much attention has been paid to 



* This is said to be the case with the drake and the hen.— Orig. 



