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Show 12 HABITS OF WORMS. CnAP. L Park, where the ground beneath was bare of all vegetation, not a single casting could be found over wide spaces, even during the autumn. Nevertheless, castings were abundant on some grass-covered glades and indentations which penetrated this forest. On the mountains of North Wales and on the Alps, worms, as I have been informed, are in most places rare ; and this rna y perhaps be due to the close proximity of the subjacent rocks, into which worms cannot burrow during the winter so as to escape being frozen. Dr. Mcintosh, however, found worm-eastings at a height of 1500 feet on Schieballion in Scotland. They are numerous on some hills near Turin at from 2000 to 3000 feet above the sea, and at a great altitude on the Nilgiri Mountains in South India and on the Himalaya. Earth-worms must be considered as terrestrial animals, though they are still in one sense semi-aquatic, like the other members of the great class of annelids to which they belong. M. Perrier found that their exposure to the dry air of a room for only a single night was fatal to them. On the CHAP. I. NOCTURNAL. 13 other hand he kept several large worms alive for nearly four months, completely submerged in water.• During the summer when the ground is dry, they penetrate to a considerable depth and cease to work, as they do during the winter when the ground is frozen. Worms are nocturnal in their habits, and at night may be seen crawling about in large numbers, but usually with their tails still inserted in their burrows. By the expansion of this part of their bodies, and with the help of the :::;hort, slightly reflexed bristles, with which their boclies are armed, they hold so fast that they can seldom be dragged out of the ground without being torn into pieces.t During the day they remain in their burrows, except at the pairing season, when those which inhabit adjoinjng burrows expose the greater part of their bodies for an hour or two in the early morning. Sick * I shall have occasion often to refer to M. Perrier's admirab}e memoir, 'Organisation des Lombriciens terrestrcs' in 'Archives de Zoolog. exper.' tom. iii. 1874, p. 372. C. F. Morren ('De Lumbrici terrcstris,' 1829, p. 14) fouud that worms endured immersion for fifteen to twenty days in summer, but that in winter they died when thus treated. t Morren,' De Lumbrici terrestris,' &c., 1829, p. 67. |