— 143 



Later on the cells, and especially 



Fig. 

 the 



14. N. gracilis. Section parallel with 

 corrugations. Lignification pointed. 

 Stage of development: Fig. 7. 



between these, as shown in Fig. 10 and 11, two sections 

 across the corrugations, a is the epidermal cell, b the prolongation 

 from the adjacent one, etc. 

 their prolongations, are thick- 

 ened and lignified, a phe- 

 nomenon otherwise somewhat 

 rare in epidermal cells. In 

 Fig. 12 (a section across the 

 corrugated rim of N. Allardi), 

 the lignified parts are shown 

 bypunctions. The lignification 

 indicated by Phloroglucin- 

 niuriatic-acid, occurs in the 

 epidermis and the middle 

 lamellæ of the subepidermal 



layer; in the large corrugations, however, the lignification also stretches 

 through all the parenchyma (Fig. 13). No doubt as well the 

 shape of the collar and its surface as the lignification may augment 

 the inflexibility of the rim. On the surface of the rim below the 



marginal glands, the 

 prolongations from the 

 epidermal cells are 

 directed towards these, 

 away from the cavity 

 of the pitcher. Here 

 the corrugated forma- 

 tions turn into the 

 typical conducting sur- 

 face, extending in the 

 various species over 

 more or less consider- 

 able part of the inner 

 pitcher- wall. In N. 



Fig. 15. N. Masterdana. Stomata of the inner side 5"*^^*'^^"''^' where the 

 of the lid. Stage of development: Fig. 1. inner part of the collar 



is very short, the con- 

 ducting surface is large (Fig. 7) ; in N. ampullaria quite the reverse takes 

 place (Fig. 6). Here, as Macfarlane (12) states, most of the inner 

 part of the collar evidently functions as a conducting surface, af- 

 fording a very insecure foothold for insects, but his description of 



