Page:An introduction to physiological and systematical botany (1st edition).djvu/226

 196 ? An observation communicated to me two years ago, in the botanic garden at Liverpool, seems to unravel the mystery. An insect of the Sphex or Ichneumon kind, as far as I could learn from description, was seen by one of the gardeners to drag several large flies to the Sarracenia adunca, and, with some difficulty forcing them under the lid or cover of its leaf, to deposit them in the tubular part, which was half filled with water. All the leaves, on being examined, were found crammed with dead or drowning flies. The S. purpurea is usually observed to be stored with putrefying insects, whose scent is perceptible as we pass the plant in a garden; for the margin of its leaves is beset with inverted hairs, which, like the wires of a mouse-trap, render it very difficult for any unfortunate fly, that has fallen into the watery tube, to crawl out again. Probably the air evolved by these dead flies may be beneficial to vegetation, and, as far as the plant is concerned, its curious construction may be designed to entrap them, while the water is provided to tempt as well as to retain them. The Sphex or Ichneumon, an insect of prey,