234 PRACTICAL LESSONS IN SCIENCE. 



tacles or filaments, which by a curious waving movement trans- 

 fer the insect to the center of the leaf where it is soon drowned 

 in the liquid, and at length is digested and absorbed. 



In the Venus fly-trap, the leaf with bristles on its edges and 

 filaments on its surface shuts up like a book thus capturing 

 insects, which are digested and absorbed. Neither of these plants 

 are sensitive to wind or rain. The most vigorous leaves rarely 

 digest more than twice, or at most three times. In these cases 

 we have illustrations of movements in plants due to some kind 

 of irritation that simulates very closely reflex action in animals. 



The common pitcher plant, sarracenia, is carniverous. The 

 mouth of the trumpet-shaped leaves is protected by a lid, the 

 inner surface of which is smeared with nectar, and in some cases 

 a pathway, honey baited, lures the insect into the pitcher where 

 they are soon drowned in the liquid secreted wholly or in part by 

 the inner membrane of the leaf. This liquid does not digest the 

 insect, but seems to accelerate decomposition, and if the plant 

 gets any nourishment from the insect, it as a saprophyte, taking 

 nourishment from decaying matter. There are several other 

 pitcher plants which destroy insects, but their process is much 

 the same as given above. The most extensive studies in this 

 direction were made by Charles Darwin. 



The Linden Family consists chiefly of tropical plants. It is 

 represented in this latitude by the lime tree or basswood. It 

 bears dull cream-colored flowers which are rich in honey. They 

 are arranged in a cluster called a cyme, which is united to a long 

 leaf-like bract ; the fruit is a woody globular two-celled nut. The 

 wood is soft, white, elastic, the inner bark rich in bast fibers. 

 The dark green leaves are roundish, serrate and somewhat heart 

 shaped at the base. It is a beautiful tree, much prized for its 

 timber and as an ornament. 



The Mallow Family consists of herbs, shrubs and trees that 

 have alternate simple, palmately veined leaves, but are best 

 known by their monadelphous stamens, which are united into a 

 tube inclosing the pistil. The flowers are regular, sepals and 

 petals five, and there is often an involucre of several green bracts, 



