342 



ASSIMILATION. 



894. Dioiiaea muscipnla, or Venus's fly-trap, grows sparingly 

 in sandy soil near Wilmington, North Carolina, and in one or 

 two other localities along the Carolina coast. Its leaf consists of 

 two rather distinct parts, the two-valved trap at the extremity, 



and a petiole-like support. It is probable that the support is not 

 a true petiole, but a leaf-blade, while the trap is a special ap- 

 pendage developed upon the tip of the leaf-blade. 



895. The spring-trap is made up of two symmetrical halves 

 meeting at a median hinge. The outer border of each half is 



plate was divided into halves by a low wooden partition, one side being des- 

 tined to be fed with meat, while the plants in the opposite half were to be 

 starved. The plates were placed altogether under a gauze case, so that the 

 'starved' plants might be prevented from obtaining food by the capture of 

 insects. The method of feeding consisted in supplying each leaf (on the fed 

 sides of the six plates) with one or two small bits of roast meat, each weighing 

 about one-fiftieth of a grain. This operation was repeated every few days from 

 the beginning of July to the first days of September, when the final comparison 

 of the two sets of plants was made " (Nature, xvii., 1878, p. 223). 



FIG. 155. A plant of Dionaea muscipula, reduced in size. 



FIG. 156. Three of the leaves of almost the natural size ; one of them open, the 

 others closed. Probably a fly is never caught by the teeth as here represented. 



