TWINERS AND CLIMBERS. 



'97 



" stoves " in Kew Gardens we remarked three or four 

 species of these climbing Amaryllids, and were 

 struck by the peculiar twisting of the petiole of the 

 leaves, which led to their closer 

 ■examination. In one species 

 (Bomarea Carderi) the leaves are 

 lanceolate, on short, flattened foot- 

 stalks. Soon after they are ex- 

 panded, and before they fall 

 back 'into their places, the 

 leaves twist over and expose 

 the under surface to the light, 

 so that the true under surface 

 becomes, practically, the upper sur- 

 face (fig. 25). The most strange 

 circumstance connected with this 

 reversal of the leaves, is the fact 

 that the under surface of the 

 leaf, as though prepared for the I 

 twisting, is smooth, and presents 

 the usual characteristic epidermal 

 cells of an upper surface, whereas 

 the true upper surface, which by 

 twisting becomes practically the Fig. 25.— Leaf of 

 under surface, is furnished with Bomarea Carderi, 



the petiole twisted 



short obtuse hairs, such as might . , , r 



in the reversal 01 



■be expected to occur on the under t h e j ea f 

 .surface of a leaf. In order that 



