260 Rev. P. Keith on the External Structure of Imperfect Plants. 



or ear, and causing smut, blight, mildew, rust; but others 

 are of excellent use, whether in the arts or in dietetics. 

 The powder of the Lycoperdons is used as a styptic ; several 

 of the Boleti make a very good tinder; the Truffle is much 

 esteemed for the rich and delicate flavour that it imparts to 

 soups and sauces; and the Mushroom, Agaricus campestris, is 

 known to every lover of good things, not only for its esculent 

 property, but also for its special utility in the preparation of 

 catsup. But in the gathering of such as are esculent, great 

 care ought to be exercised, as much mischief may arise from 

 a mistake of the species, many of the Fungi being highly poi- 

 sonous. 



Pratensibus optima fungis 



Natura est ; aliis male creditur. — Hor. lib. ii. Sat. iv. 20. 



Such is the brief sketch of the external structure of vege- 

 tables which we have thought it expedient to exhibit, with a 

 view to elucidate the gradation by which plants descend from 

 the highest and most perfect orders, to the lowest and least 

 perfect orders — " from the cedar that is in Lebanon, to the 

 hyssop that springeth out of the wall ;" or, to reverse the order 

 of our progression, and take it in the line of the ascending 

 scale — from the meadow mushroom to the mountain palm. 

 Throughout the whole of the continued climax, elevation of 

 rank is uniformly connected with complexity of structure. 

 This shows the correctness of the general views of Gaertner 

 in his controversy with Hedwig respecting the fructification 

 of the Cryptogamia, whatever we may think of his particular 

 application of them to the point at issue. Hedwig affirmed 

 that all plants whatever possess sexual organs, and produce 

 seeds, not excepting even the lowest in the scale of vegetable 

 being*. Gaertner said that some plants are destitute of sexual 

 organs, and do not produce seeds, but merely gemsf. The 

 sum of his doctrine is as follows : When the species is pro- 

 pagated by gems only, without seeds, as in the lowest orders 

 of vegetables, no sexual organs are perceptible. When the 

 seed is inconspicuous, and seemingly nothing but a mere nu- 

 cleus or embryo, then the female organs are perceptible, but 

 not the male organs, and the plants are called Aphrodites. 

 When the embryo is furnished with a radicle perceptible in 

 the seed, then also the pollen appears, but the flower has no 

 beauty; and when the embryo is found no longer constituting 

 a mere nucleus, but surrounded with its cotyledons," then there 

 is to be seen the apparatus both of flower and of sexual or- 

 gans. The first class includes plants without sex, the Con- 



* Theur. FrucL. ct Gcncr. f He Seminibus. Introd. 



