If we examine the soil of a truffle bed of Poitou, in the month of September, for instance, we find that it is traversed by great _ numbers of these white cylindrical threads, as fine as a sewing-thread, which are nevertheless composed of microscopical filaments some thousandth part of an inch in diameter. These threads, notwithstanding their minuteness, are formed of cellules, and in continuation with a flaky mycelium of the same nature, which surrounds the young truffles, forming round them a sort of white ' packing, some twentieth part of an inch thick. These filaments connect themselves directly with the external bed of the young truffle. But this enveloping network is soon destroyed; at first slowly and ‘partially, then entirely, and the truffle appears completely isolated in the soil.; € structure of the truffle is much more complicated than was formerly imagined, and we are indebted to the works of the Brothers Tulasne for much that we now know respecting the organisation of this singular vegetable. © young vegetables present very irregular sinuous cavities, partially communicating with each other, which abut, sometimes on aN unique opening corresponding to an exterior depression, Sometimes on many points of the surface. When more advanced mM age they are traversed by a double system of veins—the one white, the other coloured. The coloured veins are continued to the exterior tissue which composes the envelope. In their middle parts they are formed of a network of filaments running also in € same direction, whence issue shorter filaments perpendicular to them, whose swelling extremities become the sporangia. The White veins seem to be forced by the elongation of sterile filaments Mtermingling with the sporangia, between which the air is found :oe itself. They come out on the surface in one or many

Mts, The Spores, whose forms are much varied, though constant for the Same species, are limited in number, which rises from four toeight. Their external membrane is soft, downy, or reticulated.

The Tuber brumale, milanosporum, estivum, and mesentericum, are ‘ only Species sought for in France. 7. cebarium grows abun-oats mM various parts of England, where it is gathered about € Size of a large walnut, having a peculiar smell, and something

In Algeria 7. Jeonis occupiesof the flavour of the mushroom. the place of all the truffles of Western Europe. The large trufile, Mylitta Australis, which attains a weight of more than two pounds, is known by the natives of those regions as native bread.

The truffles especially affect a calcareous soil, or a mixture of clay and chalk. In France they abound in Poitou, Touraine, the at Brives and at Cahors. Provence, the Comtat-Venaissin,Vivarais, a shaded soil, rendered developmentThey require for their full leaves and fruit which annually fall from decomposed fertile by the the sheltering trees; at the same time it must be separated from The oak and elm are the of the roots. network the subterranean The truffle is sought for by to its growth. favourable trees most but it seems to be only out of obedi- hogs trained for the purpose, ence to its master. Having indicated the spot by slightly scratch-it out of the leaves to man the labour of digging ing it, it generally earth; but if the soil is sufficiently permeable, it does not pause its scratching until it has seized the truffle. In Burgundy the is trained and employed water-spaniel, sheep-dog, and in Italy the for the purpose. But dogs only seem to hunt the truffle fom love of, or obedience to, man. The hog is more given to egolsiit he loves the truffle, and hunts it out for his own use. he train with nose ics immovable, hog when on the traces of one, is his prize, waiting till it is dug out. Nor does he wait long, bu’ seizes and devours the odorous prey himself, with the least a hog trained to t possible delay. In Upper Provence hunting is worth two hundred francs.

The Morel, Morchella esculenta, like the truffle, belongs to the This fungus has a stalk from one to Ascomycetes. sub-order hollow cap, the size of an Bye three inches long; a spherical of a pale brown or even grey colour, and deep pitted oe: whole surface. It grows in orchards and woods, springing in early spring and summer, and is generally believed to abo ‘a in woods where fires have been made. The country an ai Germany were so persuaded of this, that they made 4 practsze was put down by law, of firing the _ os until the custom order to obtain a cropof Morels. The plant has a slight sme in cookery) a an agreeable taste; it is employed for various purposes both fresh and dried.

When the vast numbers and universal dissemination of Fungales are taken into consideration, together with their diversity of form and size, it is not surprising that botanists have been much

puzzled over them. Fries discovered no fewer than two thousand species within the compass of a square furlong in Sweden. Of

the Agarics alone above a thousand species are described. In size they range from the minute moulds which are found to produce death in the silkworm and the common house-fly (which M. Deslongchamps found in the air-cells of the Eider duck, while alive, and which Professor Owen found in the lungs of a flamingo) up to the Great Puff-ball, which attains the diameter of a foot in a single night. The different structures of Fungales.have been equally puzzling. Some writers have questioned the propriety of classing them as plants at all; and it has been proposed to establish them as an kingdom, equally distinct from plants and animals.independent Others have adopted the unphilosophical notion that they are mere fortuitous developments of vegetable matter, called into action by special conditions of light, heat, and air. But the fact that the cultivated species can be propagated with certainty, is no doubt applicable to the whole. It is argued with more reason to equivocal which have been ascribed that many of the Fungales generation, are the effects of diseased cuticle, or of the underlying tissues on which the sporules have settled. Fries thus argues against these notions. “The sporules,” he says, “are infinite, for in a single individual of Reticularie maxima I have reckoned 10,000,000, so subtle as to resemble thin smoke, as light as if raised by evaporation and dispersed in so many ways—by the sun’s attraction, by insects, by adhesion and elasticity —that it is difficult to conceive the spots from which they could be excluded.” The Cartes or Fungales which attack the wheat-plant and others ofthe Graminacese are, according to Queckett, Mucedines, to which It belongs abortans. giving the name of Ergotetia he proposes to the Concomycetes of Fries. This author considered it a diseased State of the plant itself, and placed it in his doubtful genus Spermoedia. From the investigations of Queckett it appears that © gteat mass of the Ergot, as it has been called, consists of the 8

albumen of the grain in a diseased state. Contrary to all former experiments, after the outside was scraped off, the interior under the microscope was found to be filled with globules of fatty oil; and the cause was evident. Outside of the ergotised grain were ‘found a number of small oval or elliptical bodies — about the six-hundredth part of an inch in diameter, - containing smaller granules, which were found to be sporidia of a fungoid plant, attached to filaments which developed themselves early in the growth of the grain, producing this diseased state. It grows in the interior of the ovary of the cultivated wheat (Fig. 820), and of some others of the Graminace®. At the maturity of the plant which it has posi the diseased grain is nearly ofthe size* an

its dieceniah colour, ii ane isi01 fungus would seem to have its birth in some5 manne? in the flower of the wheat-plants; the wasting influence is drawn from the — and stamens of the parent plant. “ Having,” says M. Tulasne, “subjected the pulverulent matter which filled the ovary to the microscope, and especially the parts adjacent to the periphery, which seemed to ripen more slowly, we recognised that spores attached themselves to it in great numbers by short peduncles,to a sort of trunk, or common, thin, colourless ene

Fig. 320. branches of a fragile nature, Tg. i0'r wheat.

Caries on Wheat. which seem to be re-absor or at least to disappear, as the spores they engenderadded9p" proach maturity. The tissue constituted by them is then ad ae to the ovary. This process proceeds until the whole vives de crammed with seeds of the vegetable parasite. When pease: germinates,” says M. Tulasne, in continuation, “ its retithe at o-tegument is broken at some point of its surface, bat * - i

regularity (Fig. 322, 1, 2), and a thick and flexible tube issues from ‘the opening, which continues to grow till it attains the length of about fifteen times the diameter of the spore. The shorter grains are usually crowned with a sheaf and a bundle of secondary spores designated sporidia (Figs. 323 and 324). These

Fig. 323.—Spores germinating. Fig. 324.—Sporidia.

are very slender linear bodies united into pairs in their lower Part by a short and rigid band, which gives to the pair the form of the letter H. This bouquet of spores being matured, the germs soon destroy themselves. The reproductive pairs are then isolated: from each other, spreading abroad, without altogether dissociating themselves, on the surface of the subjacent body. Some germinate quickly, and emit, especially towards their summit, very fine filaments, which quickly spread themselves (Figs. 325 and 326). ers, and those in much greater numbers, give birth to secondary Sporidia, thickish oblong or arched bodies, which appear to be the ost important agents in the multiplication of Fungales. These will be secondary sporidia, which germinate while emitting one °r many very fine filaments at certain points of their surface.” Tae Smurs.—Blights or uredines are another family of parasitic belonging to the sneer of Concomycetes. They occur s

on the diseased tissues of plants. The spores are single, often partitioned on more or less distinct spherospores, the flocci of the fruit obsolete, or mere peduncles. The Smut, properly so-called, Ustilago segetum, particularly attacks oats and barley. It develops itself of the floral envelope, in the axes of thein the parenchyma spikelet, and in the peduncles of the Graminwx. When the

Fig. 325. Bundles of Spores. Fig. 326.

wind has dispersed the spores of the parasite, the plant only remains a blackened skeleton, and scarcely recognisable. The presence of the fungale draws after it the abortion more or less complete of the organs of the flower which it has attacked, the of their normal alteration of the spike, and a notable sterility structure. Another species, Ustilago Maydis, with black spores, is equally disastrous to the cultivators of Maize or Indian corn. 418: 27 represents a spike of maize with white grains. Fig. 328 presents the vertical section of an ovary surrounded with bracts, tumified The black spots indicate the of the fungus. by the pressure formation at these points of the black powder of Ustilago Maydis. uP it producing alike stem and spikelet, attacks This fungus excrescences more or less voluminous and deformed. “In dissecting the ordinary excrescences while they are still gorged with “we find them to be formed of says M. Tulasne, juices,” with gaps, and trave of great cells, frequently parenchyma it is a structure bundles; by a small number of fibro-vascular by invested and ovary by the bracts presented to that analagous even and frequently in this parenchyma, The chasms entophytrio. cells, are filled in some cases, ae the interior of its constituting of the Ustilag? pulverescence the final before examined they are

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