Let us observe the growth of some of these Rhus’s, and we shall find that great luxuriancy of the shoots, which Kœmpfer so justly describes in his varnish-tree. One of these American ones even seems to promise the same height as the Japan Rhus; whereas this little shrubby Toxicodendron still preserves the same dwarfish slow-growing habit, that it has in its native country. This leads me, in the next place, to shew, that these two plants must be of different genus’s; the one a Rhus, and the other a Toxicodendron: and if so, according to Mr. Miller, they ought to be properly distinguished, and not ranked together, as Dr. Linnæus has done. In order to prove this, let us then examine Kœmpfer’s description of the parts of the flower, and see whether it does not answer exactly to the genus of Rhus; and whether the flowers are not male and female in themselves, that is, hermaphrodites, on the same tree. The original of Kœmpfer is as follows, p. 791 of his _Amœnitates_: “Flosculos continent pumilos, et citra coriandri seminis magnitudinem radiantes, in luteum herbaceos, pentapetalos, petalis carnosis nonnihil oblongis et repandis, staminibus ad petalorum interstitia singulis, apicatis, brevissimis, stylo perbrevi tricipite, floris turbini insidente; fructus flosculum excipit gibbosus utcunque in rhomboides figuram compressus.” Whereas Dr. Dillenius, and the authors that have copied after him, say, that his Toxicodendron has the male blossoms on one plant, and the female on the other; from whence it must evidently be another genus. It appears, however, that Dr. Dillenius was not altogether ignorant of this difference of genus in these two plants; but, rather than his Toxicodendron, which he had made agree exactly in the leaves, should not agree in the fructification, he makes the accurate Kœmpfer guilty of an unpardonable oversight, in not taking notice of the difference of the sexes of this varnish-tree in different plants: whereas we have just now shewn, that nothing can be more minutely and judiciously described, than he has done both the male and female parts of the blossom, which change into the fruit on the same plant. The original of Dr. Dillenius’s remarks on Dr. Kœmpfer’s specimen runs thus: “Planta sicca, quæ in Japonia lecta, servatur in phytophylacio Sherardino, nostræ huic specie examussim quadrat, id tantum sexus nempe differentia prætervisa fuit auctori.” Hence we find how this error came to spread, and this false synonym to be adopted by the botanic writers, who copied after Dillenius. This shews us what little dependance we can have upon the result of that meeting, which Mr. Miller mentions he had with his botanic friends; where, from the similitude of leaves only, without the parts of fructification, they determined these two plants, so different in their growth, to be one and the same plant. Mr. Miller remarks very justly, that the leaves of the same tree often vary much in shape, such as those of the poplar, sallow, _&c._