294 



ling plants alone which assume the condition of complete pitchers ; 

 and no transitions from flat leaves to hollow pitchers have been met 

 with. Low says that the old "stems of Nepenthes ampullacea falling 

 from the trees, become covered in a short time with leaves and vege- 

 table matter, which form a coating of earth about them ; they then 

 throw out shoots which become in time new plants ; but apparently 

 the first attempts to form the leaf are futile, and become only pitchers, 

 which, as the petioles are closely imbricated, form a dense mass, and 

 frequently cover the ground as with a carpet of these curious forma- 

 tions. As it continues growing and endeavouring to become a plant, 

 the lamina of the leaves gradually appear, small at first, but every 

 new one increasing in size, until finally the blades of the leaves are 

 perfect, and the pitchers, which, as the leaves developed themselves, 

 have become gradually smaller on each new leaf, finally disappear 

 altogether when the plant climbs into the trees. Tliis formation of 

 the pitcher may afford an instructive lesson to the naturalist, as, 

 though not to the same extent, the principle is perceptible in all of 

 this curious tribe, the leaves of seedlings and weak plants always pro- 

 ducing the largest pitchers." 



With regard to the functions of these curious organs, there is some 

 difference of opinion. It seems probable that the pitcher of Sarra- 

 cenia is a kind of fly-trap, serving for the capture of insects, which in 

 decay may furnish materials for the growth of the plant, or at all 

 events which may be in some way or other useful in the vegetable 

 economy. The interior of the pitcher of Sarracenia is beset with 

 long bristly hairs, pointing downwards ; at the bottom is secreted a 

 honey-like substance, which is very attractive to insects. The insects 

 experience little difficulty in reaching this secretion, but when they 

 endeavour to return, they are prevented by the downward direction of 

 the hairs, and are thus imprisoned like a rat in a wire trap. 



In connexion with this part of the subject, I may quote a passage 

 fi-om Smith's ' Introduction to Botany,' chiefly with a view of eliciting 

 information, by inquiring if the curious insect proceedings therein 

 recorded have been confirmed by any subsequent naturalist. 



" The economy of the Sarracenia, an American genus of which we 

 know four species, and of the East Indian Nepenthes distillatoria, 

 deserves particular mention. Both grow in bogs, though not abso- 

 lutely in the water. The former genus has tubular leaves which catch 

 the rain like a funnel and retain it; at least such is the nature of S. 

 purpurea, Curt. Mag. t. 849, whose margin seems dilated expressly 

 for this purpose, while the orifice of the tubular ])art just below is 



