AGATICUS is the generic name by which all the species of Mushrooms properly so called are collectively known. It com prehends such plants of the fungus tribe, as have a alp (or ;dices) of a fleshy nature, supported upon a distinct stalk, and A number of parallel unequal vertical plates or gills arising out of the cap, and indosing the particles by which the species arc reproduced ; particles which the vulgar call seeds, and botanists sporulee This genus, now divided into a largo number of sub-genera, consists of not fewer than 1000 species, inhabiting meadows, and heaths, and rocks, and masses of decaying vegetable matter, in the whole of Europe, and in many other parts of the temperate regions of the earth. Among them a large proportion are poisonous, a few are wholesome, but by far the greater number arc altogether unknown in regard to their action upon the human constitution. The species are often extremely similar; there are no means of distinguishing botanically the tribes that aro poisonous from such as are wholesome, but in every case practice is requisite to determine that point independently of general structure. It is for this reason that the use of wild nmahroorns is so dangerous. Indeed there is this most remarkable fact connected with their qualities—a fact which seems to show that their properties depend upon climate and situation, and accidental circumstances, rather than upon any specific peculiarities—those kinds which are wholesome in one country are not so in another; thus, in Great Britain, the Conunon Miudiroont Agarissa campestria (fig. 1), the Fairy-Ring Agarie, A. pratensia (fig. 2), and the A. Georgii, are the only sorts that it is quite safe to cat ; while the Fly Agarie, A. muscuriss (fig. 3), and A. rirasus (fig. 4), are extremely poisonous. But in other countries of Europe it is different. In Rome one of the few mushrooms excluded from the markets by the government inspectors in the A. campratris. In France, in Italy, and especially in Russia, a usual aliment is afforded by a great variety of species which, although very common in this country, it would be extremely dangerous to cat ; and, on the other hand, even the dangerous A. ntuscarins is a species of food in liamtchatka.
The following characters will serve to distinguish such Agaiiee as are poisonous or suspicious : 1. Such as have a cap very thin in proportion to the gills.
2. Such as have the stalk growing from one side of the cap.
3. Those in which the gills are all of equal length.
4. Such as have a milky juice.
5. Such as deliquesce; that is, run speedily into a dark watery liquid.
6. And lastly, every one that has the collar that surrounds the stalk filamentous, or resembling a spider's web.
As to the rest, the eatable kinds that can be safely employed in Great Britain are the following:— A. campestris, the Common Mushroom (fig. 1), the species that is so commonly raised artificially for food. This is readily known in any state by its fragrant odour, by which alone it may be always recognised, and the absence of which is extremely suspicious. When in a very young state it resembles little snow-white balls, which are called Buttons ; afterwards it acquires a stalk, separates its cap, and becomes shortly conical, with liver-coloured gills, and a white thick fleshy cap, marked with a few particles of gray. At a more advanced age the cap is concave, the colour gray, and the gills black ; in this state it is called a Flap. [Musrrnoou.] A. Geergii is like the latter, but its gills are always very pale, and its flavour inferior. It is said occasionally to weigh as much as 14 lbs.
A. pratensis, or oreades, the Fairy-Ring Mushroom, is so well known by its popular designation as to require no description. Well may it have gained that name ; for, in former times, there would, doubtless, be great difficulty in imagining how such productions could spring up in a few hours in the regular rings they appear in, without the aid of BOMB supernatural agency. The use to which this species is usually applied is that of being powdered and mixed with rich sauces, after having been previously strung upon a line, and dried in the shade. Dr. lladham, in his work on ' The Esculent Funguses of Britain,' shcws that a large number of other species may be eaten with impunity. Great caution is however necessary, and no person should venture on the eating of strange species unless practically acquainted with their distinctions. Dr. Badham's work contains drawings of the species which will greatly assist those who may be desirous of distinguishing the edible kinds.