204 VEGETABLE PHYSIOLOGY 



The mechanism of Cephalotus is essentially similar to 

 that of Nepenthes. 



The members of another group of plants, represented 

 by Bartsia and by Lathrcea, effect the absorption of 

 proteids in rather a different manner. Lathraea is a plant 

 which, unlike those so far described, has no chlorophyll, 

 but lives for the most of its time parasitically under- 

 ground on the roots of certain trees, only sending up into the 

 air the shoots which bear its flowers. Its stems, which are 

 entirely subterranean, bear a number of thick fleshy leaves 

 closely set together (fig. 97), which are quite colourless. 



FIG. 97. a, PIECE OF AN UNDERGROUND LEAF-SHOOT OF 

 LathrtEa squamaria. b, LONGITUDINAL SECTION 



THROUGH SAME, SHOWING THE CAVITIES IN THE LAMINA. 



(After Kerner.) 



They are curiously bent, so that the under surface is of 

 very small dimensions, and where the two surfaces join are 

 the openings of several cavities which are hollowed out in 

 the thickness of the lamina. These chambers are irre- 

 gular in shape (fig. 98), and on their surfaces are curious 

 stalked hairs which project slightly above the other cells 

 which bound the lacunar space. When an insect or other 

 small animal makes its way into one of these chambers and 

 comes into contact with the heads of these hairs, the latter 

 are stimulated, and they then send out, through openings in 

 their walls, a number of delicate protoplasmic filaments, 

 which seize upon the intruder, killing it and ultimately 

 digesting and absorbing its nitrogenous constituents. There 



