BOTANICAL .SUBJECTS. 



287 



* pitchers ' of nepenthes, perhaps, originate in much the same way, 

 from the original water-gland at the apex of the leaf." 



Strasburger and Hillhouse (" Practical Botany," p. 80) say, 

 regarding the Drosera tentacles, " Not only the epidermis, but also 

 the inner tissue of the leaf is continued into the tentacles," as is 

 shown in Fig. 117. Just so. But we may argue that the fibro- 



Fig. 117. Tentacle of Drosera rohmdifolia (Strasburger and Hillhouse) 

 (a) inner tissues of the leaf. 



vascular tissue has developed in the tentacles, not because they are 

 different in nature from glandular hairs, but because these 

 glandular hairs have developed tentacular power of movement and 

 prehension, in addition to jwwer of secretion. These tentacles 

 are highly specialized glandular hairs, with power o^ movement 

 responding to stimulus. Naturally, as this higher development 

 proceeded, the libro-vascular structures branched into these 

 originally simply cellular structures. 



