| XXX | (649) | XXX |
B O T fhpWj.that they tnjoy the faculty of generation. But yhat, pi'pcef* of argument,ayon does he employ ? ; He lays hold of another maxim of Dr Harvey : Omne vivum ex ovo, fays Haryey. “ Now,!’ adds Linnaeus, “ we have already proved that vegetables,/,/»<?; and therefore they rnu-d in like manner derive their origin from eggs. Again, no eggs can be fertilized without receiving an impregnation, from the femen of the male: And hence the eggs or feeds of vegetables mu ft likewife be impregnated by the male vegetable femen, in order to their fertilization. Further, it is an effential property ol an egg ta produce a creature of the fame fpecies with that from which itfelf was produced: Hence the feeds are the eggs pf vegetables. Befides, as the anthers and ftigmata are the only efle'ntial parts of a flower, it follows, that thefe parts are the organs of generation.” In this way Lin nasus goes on till he finds the antherse to be the teftes; the pollen, the femen; and the ftigma, the female organ of generation. But, as we have already ftiewn that Linnaeus has remarkably, failed in the proof of his firft point, namely, that vegetables are endowed with life, his fubfequent reafoning, which refts folely on the fuppofition of the living powers of vegetables, muft of courfe fail to the ground. However, allowing a fponlaneous propulfton of humours to be a pe'rfeft definition of life, philologifts are Far from being agreed* with regard to the propriety of Harvey’s fecond maxim. Omne vivum ex ovo may be ■be applied to a great variety of animals. But to this day it remains a very doubtful point, whether man and moft quadrupedes derive their exiftence from the fame fource. Hence the impropriety of drawing an analogy from a property not univerfal even among the animal creation in order to fupport an imaginary one among the vegetable tribes. When our author comes to explain the manner in which the coitus of vegetables is performed, he tells us, that the pollen may be feen lying upon.the top of the ftigma in moft hermaphrodite flowers, where it is diffolved by the moifture which conftantly adheres to that part ; and after this difiblution, that the feminal aura contained in die pollSn is abforbed by the ftigma, and fo conveyed direttly to the feeds. This account of the coitus lies open to two objedlions. fft. Admitting that the pollen may be feen adhering to the ftigmata of moft hermaphrodite plants, and admitting likewife that moifture caufes the pollen to burft and difcharge a fuhtile fluid, ftill a very natural queftion occurs with regard to the abforbing quality of the ftigma It is true, that the top of the ftigma is generally covered with moifture. But does not this indicate that the proper office of the ftigma is to fecern and propel rather than to abforb moifture ? It will be the more readily admitted, that the veflels of the ftigma are not fuited to abforb, if it be confidered that the moifture of the ftigma is fubjeded to a conftant evaporation, and of courfe muft always Hand in need of new fupplies of this liquor, which can flow from no other fource than the internal veflels of the ftigma itfelf. It may indeed be alledged, that the ftigma is furniffied with two fets of veflels, one for abforbing the feminal fluid, another for fecerning the diflolving _ Vpl. I. No. 28. ' 3'
ANY. 649 moifture. No ,body, however, has ever pretended to ftiow that the ftigma is poflefled of any peculiar veflels for abforbing; whereas every man’s eyes will convince him that it is poflefled of fecerning veffels : Hence, until the abforbing quality of the ftigma be fufficiemly proved, the poflibility of an impregnation in this way muft at leaft remain problematical. 2dly, Linnaeus makes the appearance of the pollen adhering to the ftigmata of hermaphrodite flowers an ocular demonftration of an a&ual coitus. Granting this to be an ocular demonftration of the coitus of vegetables, ffiould not the pollen be likewife feen adhering, to the ftigmata of dioicous plants ? But the appearance of pollen upon the ftigmata of dioicous plants has never yetbeen difcovered. We may, therefore, fairly conclude,that if the appearance of pollen upon the ftigmata of hermaphrodite flowers be an ocular demonftration of the coitus or copulation of plants, the want of that appearance, or. no pollen’s being ever feen upon the ftigmata of dioicous flowers, muft likewife be an ocular demonftration of the contrary ! In fupporting theoretical opinions, mankind are extremely apt to render the fubjeft ridiculous try puffiing them too far. No man ever blundered more remarkably in this refpedt than Linnaeus He is not fadsfied with attributing life and a generative faculty to plants: He muft likewife attempt to prove, that this generative faculty is fo ftrong and vigorous, as to enable them to produce hybrids or mules, by means of unnatural commixtures. In fupport of this notion, he tells us, that, when the antherae of a red tulip are cut off, and the ripe antherse. of a white one are ffiaked over the ftigma of the red one, the feeds of the red tulip, by this artificial impregnation, will produce flowers ftreaked with red and white. 0£ this fa<ft no body who knows any thing of the nature of tulips, and the changes to which the colour of their flowers are liable, will entertain any doubt. But this change of colour is evidently afcribed to a wrong caufe * for the fame change would unqueftionably happen whether the antheras of the white tulip had been ffiaked 0-1 ver the ftigma of the red one or not. When tulips blow, for the firft time, their petals are generally of one uniform colour. For feveral fucceeding feafons this original colour, continues to vary, in fo much that, by certain methods of culture, the colour of the flower may he varied without end. Linnaeus, in his fyftematic works, wifely cautions his readers not to fgund any diftiniftions upon the colour of plants, which, he dliferves, is fubjedt to fuch numberlefs alterations from culture, foil,, and other cafual incidents, that it can never furniffi the botanift with any permanent or uniform marks. ^ With what propriety^ then, Linnaeus attributes the change in the colour of this tulip to his artificial impregnation, is iiibmitted to the cdnfiueraiion of his warmeft admirers. The firft hint of mules Was taken from a* plant the figure and difpofition of wh.ofe leaves, &c. rei'embled the antirrhinum linaria, or common yellow toad-flax ; but attended with this peculiarity, that its parts of frudtification were entirely diffimilar. Linnaeus, when the plant was firft prefen ted. to. him, imagined it to he fume kind SB of
