animal origin. The Confervæ in general, are jointed, and many of them to the naked eye, but all in the microscope are singularly beautiful. The Fuci are all marine, but in every pool, rivulet, lake, and indeed wherever there is water, salt or fresh, confervæ are to be found. The species belonging to the Ulva or Laver genus are much less numerous. The umbilicated laver (Ulva umbilicalis) is well known under the name of Sloke.

With respect to the Fuci I may farther state that some of them, when wounded, throw out new fronds or leaves from the injured part. Hence, if the Fucus vesiculosus be perforated, a new leaf soon protrudes from each side of the puncture, and I have often been pleased in finding specimens of it in situations where at low water it had been trampled on, sending out many tufts of new leaves from its bruised extremities. Some trees exhibit an analo

(a) Fucus nodosus.

(b) Fucus vesiculosus.

gous proliferous tendency, and Brown says of the Papaw-tree (Carica Papaya), that it "never shoots into branches unless it be broken while young."* 5. FUNGI.

On the under surface of the cap or pileus of a mushroom (Agaricus campestris) are seen a great many perpendicular flesh-coloured laminæ or gills running from the stipe to the circumference, Fig. 87. (a). This presence of gills forms the essential character of the agaric genus (Agaricus), which is so numerous that even above three hundred British species are at present known. In the young state of the mushroom these gills are hidden from sight, for the pileus is then globular, or button-like, and thin membrane extends from its edge to the stipe, embracing the latter all round. Fig. 87. (b). The gills are the parts which produce the seeds, and the membrane alluded to protects them when in the young state, from the contact of earth and other

Fig. 87.

a

foreign bodies. Linnæus called it the Volva or curtain, and considered it, very properly I presume, as a species of calyx. When the mushroom is more advanced, we find that in consequence of the expansion, this volva cracks and gives way all round the circumference of the pileus, so that then the gills become exposed (c); and when the plant is full grown the edge of the pileus or hat has a ragged appearance, caused by the remains of the volva, while the portion of the latter originally attached to the stipe continues there in form of a ring, and hence gets the name Annulus, Fig. 87. (d)

The volva, however, is not in every case attached to the pileus, for sometimes it entirely encloses the latter like a case, and then the plant in growing bursts through, and leaves it at the bottom of the stipe, as in Agaricus volvaceus, Fig. 88., in which (a)

shows a young plant bursting through the volva, and (b) a mature one with the lacerated remains of the latter placed round its base. This form of

R

volva is called the wrapper, and in some species of the Lycoperdon genus it assumes a rather puzzling appearance, splitting into a number of acuminate elastic segments, which, as the plant expands, curve back like so many claws, and the volva being thus turned inside out, supports the fungus on its inverted centre, either on a number of pillars as in Lycoperdon coliforme, Fig. 88. (c), or sessile, as in Lycoperdon recolligens, Fig. 89. (a), and Lycoperdon stellatum, Fig. 89. (b). In the turret puff-ball (LyFig. 89.

coperdon fornicatum) a still more singular appearance is presented. In it there are two wrappers, one within the other, and these show very different dispositions, the nature of the outer leading it to split passively like the volva of the Agaricus volvaceus, but that of the inner to rebound upwards as in the Lycoperdon stellatum. They each, however, in bursting, split into four corresponding divisions, and the points of these divisions remain in contact, so that this puff-ball, when mature, is "a

globe supported upon four arched rays, the four points of the arches resting upon the four points of the outer wrapper which form an inverted arch.” * Fig. 89. (c)

There are many other genera of FUNGI besides those now mentioned, which cannot be attended to here, but the excellent plates and descriptions in Sowerby's BRITISH FUNGI will afford the student a very large fund of information on the subject; and there is every reason to expect that the attention of philosophers will be much attracted to the study of these interesting vegetables, by the able work now publishing at Edinburgh, by Mr. Greville.

Some of these vegetables are of large size, but, as in the other orders of the twenty-fourth class, a great number are very minute, and only to be examined clearly by the magnifying glass. They chiefly attack decaying animal and vegetable substances, especially the latter, and their seeds being extremely minute, are carried by the air, and hence FUNGI are to be found in almost every situation. An acute botanist might possibly even in a London cellar, or above the dome of St. Paul's, discover some rare or new species of these vegetables. +

Some FUNGI are eatable, but many poisonous,

* Withering.

+ Mr. Sowerby, speaking of the Trichia polymorpha, says, "I first found this in the outside gallery above the dome of St. Paul's Cathedral, London, April 5th, 1794, on a cindery substance."-Sowerby's English Fungi, vol. ii. pl. 180.