Insects and Frost 85 



that frost does not hurt them. Wet is probably more pre- 

 judicial to them than cold (although, as presently to be 

 noticed, water seems to have no terrors for some species 

 which ordinarily live in more or less dry surroundings), and 

 a mild winter, with its alternating frosts and thaws, more to 

 their dislike than a severe one. Chrysalides and caterpillars 

 of lepidopterous insects have frequently been known to pro- 

 duce imagines even after they had been frozen sufficiently 

 hard to be quite brittle, and the larvae, and pupae, of gnats 

 and midges must often pass through similar experiences. 

 Even higher animals, such as fish and frogs, may be frozen 

 into ice, and yet, when liberated, and thawed, appear to be 

 none the worse for their experience. In all such cases, 

 however, it is almost certain that no actual solidification of 

 the fluids of the body can have been brought about. That 

 partial freezing does take place is evident, but were the 

 " blood " to be thoroughly congealed it is probable that 

 life must cease to exist. The process of " thawing " is pro- 

 bably attended in most cases with more risk than that of 

 " freezing," and it is in order to avoid such alternations of 

 heat and cold as are attendant upon a frosty night, followed 

 by a bright sun, that insects so frequently choose the north 

 side of a tree on which to shelter during winter. 



The bottoms of some of the little pools in the peat may 

 be noticed to be alive with " Blood- Worms," * frail thread- 

 like bodies, which, waving in little crowds from their in- 

 geniously constructed tunnels, seem to dye the undisturbed 



1 Not to be confounded with the entirely distinct Water Worms (Tubifex 

 rivularum}, to which they bear some slight superficial resemblance. Little 

 colonies of the latter may also be detected amongst the peaty "mud" in 

 many of these same pools, although only a day or two ago the water was 

 covered with ice, and ere a few weeks have passed it will, in normal circum- 

 stances, all be dried up, and the bottoms of the erstwhile pondlets baked by 

 the summer sun. Such of the midgy larvse as are destined to survive will 

 have completed their final metamorphosis before the time of drought arrives ; 

 but what then becomes of the water- worms, which know no such change, and 

 to whose existence dampness at any rate, if not actual water, is supposed to 

 be essential : what useful part in the economy of Nature they are designed to 

 accomplish here : or how the stock is renewed, when the depressions once more 

 become converted into miniature lakes, are further "matters of curious inquiry" 

 which might usefully engage our attention. At present it is sufficient to note 

 that neither " fantastic summer's heat " nor winter's cold interferes with the 

 continuance of the race, and the one fact is almost as astonishing as the other. 



