PRELIMINARY OBSERVATIONS.

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species are distinguished from Clavaria by their having theirfruit contained in perithecia, which are very conspicuous be-neath the cuticle when the plant is divided.

A very distinct division contains some of the productionswhich are commonly known under the name of Mildew. Thesein a young state are white and mealy, and are known as HopMildew, Rose Mildew, etc.; but as they grow, they form firstyellow, then black, speck-like sacs, which contain a differentform of fruit. These sacs are attached to abundant filaments, andtherefore approach somewhat in appearance to Moulds. Theyare called Perisporiacei, from the typical genus Perisporium.

There is yet another small group, of which one genus con-sists of Fungi which grow principally on animal substances, asdecaying hoofs, horns, feathers, etc. These, however, are notvery common, and are therefore little known. The group iscalled Onygenei, a name alluding to the growth of one of thespecies on hoofs of animals.

We have still another set of productions which rank amongstFungi, some of which are popularly known. They are theSporangium-bearing Fungi noticed above, p. 17. They consistof two groups only, the first of which comprises the dark felt-like Fungi, which run over the leaves of living trees. They areuncommon in Great Britain, and it is probable that they are,in general, conditions of other Fungi. They are called Anten-nariei, from the threads of some of them when magnified re-sembling the antennae of beetles. The other contains thoseMoulds which have distinct sacs on their threads, and notnaked spores. The common Moulds of paste and of rottingpears are well-known instances. The finest British exampleis Mucor nitens, which grows on fatty substances, and attainsa considerable size. Most of the species, however, are merelymicroscopic objects.

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