312 DION^A MUSCIPULA. Chap. XIII. 



creasing darkness ; and one of my sons actually saw a 

 small insect thus escaping. A moderately large in- 

 sect, on the other hand, if it tries to escape between 

 the Lars will surely be pushed back again into its 

 horrid prison with closing walls, for the spikes con- 

 tinue to cross more and more until the edges of the 

 lobes come into contact. A very strong insect, how- 

 ever, would be able to free itself, and Mrs. Treat saw 

 this effected by a rose-chafer (Macrodactylus siibspi- 

 nosiis) in the United States. N'ow it would manifestly 

 be a great disadvantage to the plant to waste many 

 days in remaining clasped over a minute insect, and 

 several additional days or weeks in afterwards re- 

 covering its sensibility; inasmuch as a minute insect 

 would afford but little nutriment. It would bo 

 far better for the plant to wait for a time until a 

 moderately large insect was captured, and to allow all 

 the little ones to escape ; and this advantage is 

 secured by the slowly intercrossing marginal spikes, 

 which act like the large meshes of a fishing-net, 

 allowing the small and useless fry to escape. 



As I was anxious to know whether this view was 

 correct — and as it seems a good illustration of how 

 cautious we ought to be in assuming, as I had done 

 with respect to the marginal spikes, that any fully 

 developed structure is useless — I applied to Dr. Canby. 

 He visited the native site of the plant, early in the 

 season, before the leaves had gro^vn to their full size, 

 and sent me fourteen leaves, containing naturally 

 captured insects. Four of these had caught rather 

 small insects, viz. three of them ants, and the fourth 

 a rather small fly, but the other ten had all caught 

 large insects, namely, five elaters, two chrysomelas, 

 a curculio, a thick and broad spider, and' a scolo- 

 pendra. Out of these ten insects, no less than eight 



