PHYLLOTAXY. 



673 



and the digits lock tightly together, thus preventing the escape of the prey. 

 The droseras, sarracenias, and nepenthes also kill their food. The sarracenias 

 form curious cups, into which insects m< DEPENDING ON POINT. 



are enticed in search of fluid, and then, 

 as in the case of the house-haunting Obtuse (Dock), 

 cockroach, they cannot get out again. 

 The nepenthes have a cup and lid for Mucronate (Holly), 

 insect-catching, and within the cup a 

 liquid is secreted. Retuce (Snowball). 



We will close this portion of our 



subject with a quotation from a recent Emarginate (Bladder Senna), 

 article upon botany referring to leaf ar- 

 rangement. The writer says : 



" Efforts have been made to determine the laws to which these various 

 modes of leaf-arrangement may be referable. The result is 

 found in the doctrine of ' Phyllotaxy,' as it is called, the 

 fundamental principle of the whole being that Nature, in 

 the disposition of the leaves upon the stem, works upon 

 precisely the same idea as that which is set forth so dis- 

 tinctly and elegantly in the common pine-cone ; and, on a 

 minor scale, in the beautiful cone of the 

 female hop ; not to mention the quasi- 

 cones of many species of tropical palm, 

 such as the Sagus and the Mauritia ; nor 

 to mention either, the very delicate re- 

 petition of the whole series in the florets 

 of the Rudbeckia and the ripening fruits 

 of Chaucer's daisy. In every one of the flower and 



fruit arrangements mentioned, 

 the idea is the spiral, the 

 same sweet old fashion which 

 we have had in the twining 

 stems of the convolvulus, the 



Fig 767. Leaf of Nepenthes. 



woodbine, and the scarlet 



bean ; which comes out again in many a sea-shell, 

 and in human ringlets ; and this idea, according 

 to ' Phyllotaxy,' governs the position of the leaves. 

 Following alternate leaves up the stem, their 

 sequence is clearly spiral. Through the non-deve- 

 lopment of internodes, they are brought closer and 

 closer together ; and even when the entire mass 

 of foliage is concentrated and condensed into the 

 rosulate form, as in the houseleek and the Eche- 

 verias, the spiral prototype is still distinguishable. 

 Fig. 7 66.-sarracenia. The whole matter has been reduced to one of 



Fig. 765. Leaf of 

 Dionae. 



