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Show 56 HABITS OF WORMS. CIIAP. II. ciently tender. They generally seized the thin edge of a leaf with their mouths, ?etween the projecting upper and lower hp ; the thick and strong pharynx being at the same time as Perrier remarks, pushed forward ' . within their bodies, so as to afford a p01nt of resistance for the upper lip. In the case of broad flat objects they acted in a wholly different manner. The pointed anterior extremity of the body, after being brought into contact with an object of this kind, was drawn within the adjoining rings, so that it appeared truncated and became as thick as the rest of the body. This part could then be seen to swell a little ; and this, I believe, is due to the pharynx being pushed a little forwards. Then by a slight withdrawal of the pharynx or by its expansion, a vacuum was produced beneath the truncated slimy et1d of the body whilst in contact with the object ; and by this means the two adhered firmly together.* That under these circumstances a vacuum was produced was plainly * Claparede remarks (' Zcitschrift flit' wissenschaft. Zoolog.' B. 19, 1869, p. 602) that the pharynx appears from its structure to be adapted for suction. CHAP. II. 'l'IIEIR MANNER OF PREIIENSION. 57 seen on one occasion, when a large worm lying beneath a flaccid cabbage leaf tried to drag it away; for the surface of the leaf directly over the end of the worm's body became deeply pitted. On another occasion a worm suddenly lost its hold on a fiat leaf; and the anterior end of the body was momentarily seen to be cup-formed. Worms can attach themselves to an object beneath water in the same manner; and I saw one thus dragging away a submerged slice of an onion-bulb. The edges of fresh or nearly fresh leaves affixed to the ground were often nibbled by the worms ; and sometimes the epidermis and all the parenchyma on one side was gnawed completely away over a considerable space; the epjdermis alone on the opposite side being left quite clean. The veins were never touched, and leaves were tbus sometimes partly converted into skeletons. .As worms have no teeth and as their mouths consist of very soft tissue, it may be presumed that they consume by means of suction the edges and the parenchyma of fresh leaves, after they have been softened by the |
