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Show 36 HABITS OF WORMS. CHAP. I. Food and Digestion.-Worms are omnivorous. They swallow an enormous quantity of earth, out of which they extract any d1gestible matter which it may contain; but to this subject I must recur. They also consume a large number of half-decayed leaves of all kinds, excepting a few which have an unpleasant taste or are too tough for them; likewise petioles, peduncles and decayed flowers. But they will a1so consume fresh leaves, as I have found by repeated trials. According to Morren* they will eat partic1es of sugar and liquorice; and the wonns which I kept drew many bits of dry starch into their burrows, and a large bit had its angles well rounded by the fluid poured out of their 1nouths. But as they often drag particles of soft stone, such as of chalk, into their burrows, I feel some doubt whether the starch was used as food. Pieces of raw and roasted meat were fixed several times by long pins to the surface of the soil in my pots, and night after night the worms could be seen tugging at them, with the edges of the pieces engulfed in their mouths, so that much was consumed. * 'De Lumbrici terrestris,' p. 19. CHAP. I. FOOD AND DIGESTION. 37 Raw fat seems to be preferred even to raw meat or to any other substance which was given them, and 1nuch was consumed. They are cannibals, for the two halves of a dead worm placed in two of the pots were draO' d • . b~ Into the burrows and gnawed; but as far as I could j~dge, they prefer fresh to putrid meat, and In so far I differ from Ilo:ffmeister. ~eon Fredericq states* that the digestive flmd of w. orms is of the same nature as the pancreatiC secretion of the hicrher animal . an d t h' b s' IS conclusion agrees perfectly with th kinds. o~ :ood which worms consu~e. Pan~ creatw JUice emulsifies fat, and we have just s~en how greedily worms devour fat; it dissolves fibrinJ and worms eat raw meat. it converts starch into grape-sugar with wonderful rapidit!J and we shall presently show that the dJgestive fluid of worms acts on starch.t But they live chiefly on half-decayed leaves. and thes~ would be useless to them unless the; could digest the cellulose formino· the cellwalls; for it is we1l known that all ~ther nutri- . "'0'A r c hl"v es.de Zoologic cxperimentalc,' tom. vii. 1878, p. 394. f tp n.the actwn of the pancreatic ferment see 'A 'l'cxt-n k o hyswloOo"Y , 'bY M"I C h ac l Foster, 2nd edit. p' p. 198_203. 18o7o8 • |