Kingdom; in which respect they differ from Lichens, which very commonly grow upon

It is not merely alterations of the epidermis of plants which assume the appearance of Fungi; galls also, or tubercles caused by the attacks of insects, bear occasionally a wonderful resemblance to such bodies; so much so indeed, that

Fig. XV.-Oak Spangles.-3. Upper side; 4. under side; 2. silk button galls; 6. a section of one with a larva in the interior. See Curtis in Gardeners' Chronicle, 1843, p. 52.

nature are the Guêpes végétantes of the West Indies; the Muscardine, which is so destructive to silkworms, and on which so many excellent Memoirs have been written; the mould, which so often causes the death of the common house-fly in autumn; and above all, the curious instances which have been recorded of the development of moulds in the mucous membrane of the viscera of vertebrate animals, and in certain cutaneous disorders in man.

Mouldiness, for instance, has been found by M. Deslongchamps on the internal surface of the air-cells of an Eider-duck while alive; and Mr. Owen observed a similar growth in the lungs of a Flamingo.-Ann. Nat. Hist. viii. 230. Col. Montagu had previously remarked it in the same situation in the Scarp-duck.-16. ix. 131. Gruby observed the even where the little grub which produced them has vanished, the total absence of all parts of fructification will at once decide the point. If, for instance, the cup-shaped gall, which is so common on Oak leaves, be the object in question, any one who has once examined the hymenium of a Peziza, and

observed the fructifying cells arranged vertically like the pile of velvet, with their row of eight mostly elliptic sporidia, cannot for a moment be deceived. It does, however, sometimes happen that galls are extremely like Fungi; a remarkable instance of which has been figured in the Transactions of the Linnean Society. It was sent by Mr. Macleay, from Cuba, on the leaf of some plant of the Natural Order Ochnacer. In this case there is not merely an extraordinary development of the external cellular tissue, but the gall is formed within the substance of the leaf, and after a time bursts through the skin, and presents a little ovate body with a crenate border, and within this an operculum which is perforated, or at least apparently perforated in the centre, so as to present a very close resemblance to some strange para

site. And, as if to make the resemblance to some Fungus more close, the gall appears to make an abortive attempt to penetrate the opposite surface of the leaf, almost exactly in the way which is observable in the curious production which is sometimes so injurious to Pear-trees. But even in this case, where there is no trace of the inclosed grub or pupa, the texture of the walls of the gall is so different from that of Fungals that it can scarcely deceive, on any moderately accurate examination.

There is yet another production, referred to Fungals by Bernhardi, and after him by Fries and others, which, however, is probably to be regarded neither as a disease nor parasite. These are the tuberous bodies so common on the roots of leguminous plants. Their exact nature and use at present is not known; but a Memoir on them has been prepared some time by M. Desmazières. They appear a very few days after the germination of the seeds, and are accompanied by a little bed of vessels, in which they are nestled. At an early stage of growth, the contents of their cells become blue, when treated by iodine, which is not the case when their pulpy contents have acquired a salmon-coloured hue, when in some cases the granules are simple and oblong, in others forked. There can be little doubt that they are of some importance to the plant, though they are not, like common tubers, destined for the reproduction of the species, as they pass through the phases of vegetation in a short time, and soon become ruptured and discharge their contents. No insect has ever been observed in them, nor indeed does it at all appear that they are of the nature of galls. It is possible that in very dry situations, and in time of drought, the nutriment collected in them is serviceable to the plant; but this is very doubtful.

Fig. XVI.-Galls on the leaf of an Ochnaceous plant.

Fig. XVII.-Woolly Oak-gail, produced by Cynips Quercus ramuli.-Curtis.)

crusts of Tinea favosa and Porrigo lupinosa to be accompanied by moulds, Comptes Rend. Aug. 1841; and these observations have been extended by Dr. Bennett, Trans. Roy. Soc. Ed., vol. xv., Part 2, p. 277, who has also observed a mould growing on the lining membrane or cheesy matter of tubercular cavities in the lungs of man; as also the development of a mould on the skin of living gold-fish. Much information will be found on the subject in the place above quoted.

In their simplest form Fungi are little articulated filaments, composed of simple cellules placed end to end; such is the mouldiness that is found upon various sub

stances, the mildew of the Rose-bush, and, in short, all the tribes of Mucor and Mucedo; in some of these the joints disarticulate, and appear to be capable of reproduction; in others, spores collect in the terminal joints, and are finally dispersed by the rupture of the cellule that contained them. In a higher state of composition, Fungi are masses of cellular tissue of a determinate figure, the whole centre of which consists of spores attached, often four together, to the cellular tissue, which at length dries up, leaving a dust-like mass intermixed more or less with flocci, as in the puffballs, or sporidia contained in membranous tubes or asci, like the thecæ of Lichens, as in the Sphærias. In their most complete state they consist of two surfaces, one of which is even and imperforate, like the cortical layer in Lichens; the other separated into plates or cells, and called the hymenium, to whose component cells, which form a stratum resembling the pile of velvet, the spores are attached by means of little processes, and generally in fours, though occasionally the number is either less or greater. Many of these cells remain barren; but after a time there

Fig. XXI.

is a succession of fertile cells constantly making its appearance above the surface of the hymenium; and, what is more remarkable, the spicules or sterigmata, which support and give rise to the spores, have been observed by Corda to produce a succession of fruit, a new spore being produced where the old one had fallen. This, he informs us, is very easy of observation in Agaricus pluteus. Besides the barren and fertile cells, other bodies are observed which have been supposed by authors to perform the office of anthers. These have long been known in the

dunghill Agarics, but they appear to be pretty generally distributed. The true structure of the more perfect Fungi has only been recognised within a few years, though Müller, half a century since, gave a correct figure of it in Agaricus comatus, and there are indications of it scattered through many works. Léveille's Memoir in Annales des Sciences Naturelles, that of Berkeley in the Annals of Nat. History, of Phoebus in Nova Acta Cæs. Leop., and those of Berkeley and Tulasne in the Ann. of Nat. Hist. and Ann. des Sc. Nat. on the fructification of Lycoperdons, as also that of the Messrs. Tulasne on Hypogeous Fungi, may be consulted on this subject.

Upon this kind of difference of structure, Fungi have not only been divided into distinctly marked tribes, but it has been proposed to separate certain Orders from them under the name of Byssaceae, Gasteromyci, and Hypoxyla: the first comprehending the filamentous Fungi found in cellars, and similar plants; the second Lycoperdons and the like; and the third species which approach Lichens in the formation of a distinct nucleus for the sporules, such as Sphæria. But Fries considers the first as a distinct group, and the two last as Fungi.

Some writers have questioned the propriety of considering Fungi as plants, and

Fig. XXI.-Botrytis curta.

Fig. XXII.-1. Spore-stalk of Agaricus elixus, with its four long sterigmata and small spores; 2. spore-stalks of Ag. semiovatus, with spores in various states of development; 3. asci and sporidia of Helvella elastica; 4. sporidium of Tuber magnatum (Piedmontese Truffle), from a sketch by Dr. Montagne; 5. sporidium of Peziza aurantia, with its two nuclei; 6. single sporidium of Helvella elastica, with a large globose nucleus.

have proposed to establish them as an independent Kingdom, equally distinct from ⚫ animals and vegetables; others have entertained doubts of their being more than mere fortuitous developments of vegetable matter, called into action by special con

ditions of light, heat, earth, and air-doubts which have been caused by some remarkable circumstances connected with their development, the most material of which are the following: they grow with a degree of rapidity unknown in other plants, acquiring the volume of many inches in the space of a night, and are frequently meteoric, that is, spring up after storms, or only in particular states of the atmosphere. It is possible to increase particular species with certainty, by an ascertained mixture of organic and inorganic matter exposed to well-known atmospheric conditions, as is proved by the process adopted by gardeners for obtaining Agaricus campestris, a process so certain, that no one ever saw any other kind of Agaricus produced in Mushroom-beds, except a few of the dunghill tribe, where raw dung has been placed near the surface of the bed; this could not happen if the Mushroom sprang from seeds or sporules floating in the air, as in that case many species would necessarily be mixed together; Fungi are often produced constantly upon the same kind of matter, and upon nothing else, such as the species that are parasitic upon leaves: all which is considered strong evidence of the production of Fungi being acci-· dental, and not analogous to that. of perfect plants. Fries, however, whose opinions must have great weight in all questions relating to Fungi, argues against these notions in the following manner : "The sporules are so infinite (in a single individual of Reticularia maxima I have. reckoned above 10,000,000), so subtile (they are scarcely visible to the naked eye, and often resemble thin smoke), so light (raised, perhaps, by evaporation into the atmosphere), and are dispersed in so many ways (by the attraction of the sun, by insects, wind, elasticity, adhesion, &c.), that it is difficult to conceive a place from which they can be excluded." I give his words as nearly as possible, because they may be considered the sum of all that has to be urged against the doctrine of equivocal generation in Fungi; but without admitting, by any means, so much force in his statement as is required to set the question at rest. In short, it is no answer to such arguments as those just adverted to. It seems to me that a preliminary examination is necessary into the existence of an exact analogy between all the plants called Fungi; a question which must be settled before any further inquiry can be properly entered upon. That a number of the fungus-like bodies found upon leaves are mere diseases of the cuticle, or of the subjacent tissue, is by no means an uncommon opinion; that many more are irregular and accidental expansions of vegetable tissue in the absence of light, is not improbable; and it is already certain that no inconsiderable number of the Fungi of botanists are actually either, as various Rhizomorphas, the deformed roots of flowering plants growing in cellars, clefts of rocks, and walls; or mere stains upon the surface of leaves, as Venularia grammica; or the rudiments of other Fungi, as many of Persoon's Fibrillarias. Those who are anxious to inquire into these and other points, are referred to Fries'

Fig. XXIII.

Fig. XXIII.-Aseroe pentactina.

works generally, to the various writings of Nees von Esenbeck, and to the Scottish Cryptogamic Flora of Greville. In the ensuing list of genera, I have chiefly availed myself of the writings of Fries. The disposition, however, of the genera has been modified in conformity with recent discoveries as to the real structure of the more highly organised species, and the numerous discoveries of Corda, where their affinities were at all clear, have been recorded. That it must be a matter of extreme difficulty to form any precise opinion concerning Fungi, without long experience, will be apparent from the observations of Fries upon the genus Thelephora. (Elenchus, p. 158.) He asserts that out of mere degenerations or imperfect states of Th. sulphurea, the following genera, all of which he has identified by means of unquestionable evidence, have been constructed; viz., Athelia of Persoon, Ozonium of Persoon, Himantia of Persoon, Sporotrichum of Kunze, Alytosporium of Link, Xylostroma, Racodium of Persoon, Ceratonema of Persoon, and some others. Th. Fr. Nees von Esenbeck also assures us that the same fungoid matter which produces Sclerotium mycetospora in the winter, develops Agaricus volvaceus in the summer. It would thus seem that the opinions of those who have asserted that the species or genus of a Fungus depends not upon the seed from which it springs, but upon the matrix by which it is nourished, are at least specious; especially if we take the above fact in connection with the experiments of Dutrochet, who obtained different genera of Mouldiness at will, by employing different infusions. He says that certain acid fluids constantly yield Monilias, and that certain alkaline mixtures equally produce Botrytis. Ann. des Sc. 2 ser. 1.30. For a description of the gradual development of an Agaric, see this ingenious observer's Memoir in the Nouv. Ann. du Mus. vol. iii. p. 76. For the views of Unger upon spurious Fungi, which he considers nothing but morbid conditions (eruptions) of vegetable matter, see the Ann. des Sc. vol. ii. n. s. 209; and Berkeley's remarks thereupon, in Hook, Brit. Fl. vol. ii. pt. 2, p. 361.

Since, however, the remarks of Unger were published, Léveillé and Corda, almost at the same time, and quite independently of each other, made their discovery of the Mycelium of Uredines and Puccinia, and Corda has

succeeded in making many germinate. Unger's speculations, therefore, must be considered as much invalidated, at least so far as their being mere transformations of the cellular tissue, as is the case in Erineum. Whether animal and vegetable bodies are ever produced without pre-existent germs, belongs to quite another question. And, as regards the genera Ozonium, Himantia, &c., they are now regarded by all good mycologists as mere barren states, or anamorphoses of other species; and the same is probably true of many of the more anomalous Fungi; and the observations of Léveillé, in the Annales des Sciences Naturelles, go very far to prove that the whole genus Selerotium belongs to the same category. Some of them, as Aerospermum cornutum, and Sclerotium mycetospora, are undoubtedly mere forms, and have no right whatever to be considered as species; others arise from the condensation of the filamentous tufts of moulds; others, as S. lotorum, are little excrescences upon the roots, and the celebrated Ergot is produced by the action of a minute parasite. There is indeed a difficulty about such species as Sclerotium scutellatum; but there is little doubt that, in the main, Léveillé's observations, even though from the nature of the subject the proof is not rigorous, are founded in fact. Some supposed species of Uredo are merely the young of Puccinia, Aregma, &c.; but there are also true species of the genus. See Henslow, Journ. of Roy. Soc. Ag. 1841, vol. ii. p. 2.

Fig. XXIV.

Kützing, in his Prize Essay on the Transformation of Plants, asserts that from one and the same organic material, even when it has acquired form and colour, different vegetables may be developed, which, according to the circumstance of the surrounding medium, aro Algals, Fungi, Lichens, or Mosses; and that even the spores of these, when pro

Fig. XXIV.-Puccinia graminis (common Mildew), with its spawn or mycelium penetrating the cell of the plant on which it grows.