The third lecture of the autumn series Dr. Roth-rock delivered in Horticultural Hall, Fairmount Park, recently. It was by special request that the subject, Mushrooms and Toadstools, was taken up.

The lecturer said he had : " Nothing to add to what the daily papers had recently published. The Ledger especially had given much exact and valuable matter concerning this group of plants. He hoped simply by calling attention to some illustrations, to give a few more people a more clear notion as to the appearances of some very good and some very bad plants among these fungi. It was exactly a case of ' line upon line ' on a most important subject.

" Some men could eat no species of fungus without sickness, but as there is hardly any one article of food which suited all people equally well, this fact should not lead to mushrooms, - which most persons can eat, - being denounced. On the other hand, by proper preparation many fungi which are usually poisonous can be made edible. Men generally regard toadstools as simply poisonous mushrooms. The above facts, however, show that as one man's food may be another's poison, such a distinction between mushrooms and toadstools cannot stand. It were well if it could be dropped entirely.

" People imagine that as there is no sign by which we may always recognize a poisonous fungus, they are, therefore, more difficult to detect than poisonous flowering plants. The fact is, that in each case there are certain distinguishing marks belonging to each species, and knowing these, one may readily determine whether or not the plant is poisonous. You must learn to recognize some edible fungi as certainly as you recognize apples or peaches, and you can do it just as easily.

" Two mushrooms with gills were then drawn on the board. One was the Agaricus campestris (the common edible mushroom); and the other was the Agaricus (or Amanita) vernus, which has a recent sad interest in connection with the poisoning of a family at Shenandoah, in this State.

"The first, Agaricus campestris, grows in pastures, lawns, lanes, but not in the woods. In its best (and safe condition) its expanded cap is white, and a little downy above, and the gills beneath are pink or purple, but not white. The stem is nearly solid; does not rise out of a cup (volva) at the base, and has a ring about it in the upper half. These characters will not lead one into danger.

"The poison, Amanita (Agaricus vernus), has white gills, is white, yellow, bright or pale red above, and at first has a conspicuously marked ring around the stem; and the stem rises out of a cup (volva) at its base. Keep clear of all such lungi, whether poisonous or not. Unless they are certainly known to you, let them alone. That is safe advice to act upon.

" Puff balls were next alluded to. These are usually white, roundish or oblong, and vary in size from an inch in diameter to over a foot, or, in extreme instances, to a yard in diameter. At first they are, inside, solid, white and edible; then yellowish, spongy and suspicious; lastly, black, powdery, and unfit to eat. There are many different kinds with us, but before they turn yellow all are safe as food. They may grow on stumps, on sandy soils or on grassy banks, especially after a drenching rain in the latter part of summer. Cook them as you would an egg-plant.

"The next group spoken of was that known as Boletus. Its characteristic is the pores on the under side of the cap. Split this cap and the pores are seen to be the entrances of a mass of closely compacted tubes, which lie straight and parallel, and are open below. There are a number of species of Boletus. All are said to be edible. It may be so; but the lecturer only advised general use of one - Boletus edulis - because, first, it was known to be safe; because, secondly, it was not rare; and lastly, because it was easily recognized. Picture to yourself a fungus from three to six inches high, with a stout stem, which is somewhat swollen below, the cap thick, chestnut-colored above, and mouths of the tubes below yellow or yellowish green. Whatever others may say, unless you are sure of the species, eat no Boletus with red or reddish tubes.

" The lecturer gave, he said, but a few out of the many which he might have named. What advice he gave, however, was safe.

"There was a point he insisted upon - that, as fungi, which were edible and delicious and nutritious, were probably more abundant here than in Europe, where they were an important article of food, it was in the interest of the community that every one should know them. Every public school in this State should have, where every child could see them, plaster models, life size and color, of the edible and the poisonous species. This idea could easily be realized and would involve almost no expense, whilst its practical benefits would be larger than we can at present conceive of. Even the Chinese government prints and distributes broadcast over the land what is known as the Anti-Famine Herbal, a book describing nearly 500 species of plants, which, in times of scarcity, may be utilized as food. Are we still to remain in this respec: below these, whom we consider barbarians ?"

[The above excellent synopsis of one of the Michaux Lectures in Fairmount Park was made for the Public Ledger of Philadelphia.

We may add that to those who desire further knowledge, the colored plates of Edible and Poisonous Mushrooms recently issued by Messrs. Prang & Co., will be very seasonable. - Ed. G. M].