- Fungi. The species are very numerous, but their identification is not easy, and requires serious application. The two figured are exceedingly common in some districts. Various species of Cup-moss (Cladonia) will be met on heaths, sandy hedge-banks, etc. They have a flat crust-like base, from which arise pale grey tubes or cups, bearing at their tips the bright scarlet, pinky-brown, or even black fruits. A more common form in woods and on banks is Cladonia pyxidata, with the tube greatly increasing in width upwards. Cladonia rangiferina is the well-known Reindeer-moss, of inestimable value in extreme Northern latitudes as the food of the useful animal whose name it bears; it may be found in abundance in this country on heaths and hillsides covering the ground beneath the heather.

The other species figured in our plate, the Wall-lichen (Physcia parietina), is also very common, forming the familiar orange stains upon walls and maritime rocks. A closely allied species, the grey Parmelia saxatilis, is common on tree-trunks: it has been used time out of mind in the production of a brownish-red dye for wools. Several others of the same genus are valuable in a similar direction: our own Parmelia perlata, which grows on tree trunks, is largely imported from the Canaries as a dye-weed, and has been sold at as high a rate as 200 per ton.

Lichens are generally of slow growth and long life. Mr. Berkeley kept watch upon a patch of Lecidia geographica for twenty-five years, and found little change in it all that time. The Rev. Hugh Macmillan recounts how he found on the top of Schiehallion a species of lichen encrusting quartz rocks, which exhibited beneath the lichen the marks of glacial action as distinct and unchanged by atmospheric effects as though the glacier had only passed over them yesterday. He suggests that the lichen may reckon its days back very nearly if not quite to the glacial period in Britain!

There are upwards of a thousand British species, and the best list of them will be found in "Crombie's British Museum Catalogue of Lichens," of which the first part was published in 1894.