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Show 80 IIABITS OF "'WORMS. C.JnAP. II. petioles were pulled out of worrn burrows ear ly 1. n J anuar y , and of these 51 ·5 per cent. had been drawn in by the base, and 48·5 per cent. by the apex. This anomaly was b~w-ever rea d1.l y ex~ plained as soon as the tlnck basal part was exarnined; for in 78 out of 103 petioles, this part bad been gnawed b! wor.ms, just above the horse-shoe shaped artiCulatwn. 'rn most cases there could be no mjstake ab?ut the gnawing; for ungnawed petioles whiCh were examined after being exposed to the weather for eight additional weeks had not become more disintegrated or decayed .near the base than elsewhere. It is thus evident that the thick basal end of the petiole. is drawn in not solely for the sake of plugging up the mouths of the burrows, but as food. Even the narrow truncated tips of some few petioles had been gnawed ; .and this was the case in 6 out of 37 whJCh were examined for this purpose. Worms, after having drawn in and gnawed th~ basal end, often push the petioles out of their ~urrows; and then drag in fresh ones, eitl1er by the base for food, or by the apex for plugging up the 1nouth more effectually. . T~us, out of 37 petioles inserted by their tips, CrrAP. 11. 'l'IIEIH JN'l'ELLlOENOE. Rl 5 bad been previously drawn in by the ba e, for this part had been gnawed. Again, I collected a handful of petioles lying loo, e on the ground close to some pln()"ged-up bu.Trows, where the surface was thickly strewed with other petioles which apparently had never been touched by worms; and 14 out of 4 7 (i.e. nearly one-thh·d), after havillg had their bases gnawed had been pushed out of the burrows and wore now lying ou the ground. From these several facts we may conclude that worms draw in some petioles of the ash by the Lase to serve as food, and others by the tip to plug up the mouths of their burrows in tho most efficient manner. The petioles of Robinia pseudo-acacia vary from 4 or 5 to nearly 12 inches in length ; they are thick close to the base before the softer parts have rotted off, and taper m11c11 towards the upper end. They are so flexible that I have seen some few doubled up and thus drawn into the burrows of worms. Ullfortunately these petioles were not examined until February, by which time tho softer parts had completely rotted off, so that it was im-u |
