60 THE STKUCTURES OF PITCHER PLANTS. 



downwards, and in the same position as the hoods of the glands lower 

 down. Occasionally at a little distance below one of these markings an 

 epithelial cell can be seen enlarged, and with an increase of protoplasm, 

 sometimes even having a semblance of segmentation, which makes it 

 appear as if it were making an effort to become a gland. The crescentic 

 markings on section can be seen to be formed by the doubling of one 

 epithelial cell under another, so that beyond doubt they are rudimentary 

 hoods. These hoods, as will be afterwards seen, have a very important 

 purpose, but even in this rudimentary condition they would prove 

 serviceable by affording an increase of absorbent sm-face, just as the 

 valvulse conniventes do in the intestine. These latter structures are found 

 in quite as rudimentary a state in the intestine, as those by which the 

 perfect hoods are represented in the upper surface of the Nepenthes' 

 pitcher. 



The line of commencement of the glands (in a pitcher where there 

 is a non-glandular surface) is quite abrupt, and corresponds with the 

 ampullary enlargement generally seen outside. From this point the 

 glands are found distributed with great regularity, and increasing in size 

 towards the bottom of the pitchers, where, on the lower or greater 

 curvature, the largest are always found, that spot being, of course, the 

 position in which the gland function will most frequently be called into 

 action. These glands resemble in structure very closely those seen in 

 Drosera and Dionsea, though, of course, their details differ somewhat. 

 They are sessile, and are placed in depressions of the parenchyma, lined 

 with epithelium, which, at the top of the pit, is produced into a double 

 fold of modified epithelium, between the cells of which run intercellular 

 spaces, and each gland is placed on a twig of spiral tissue, in this 

 arrangement being identical with the glands of Drosera. It requires 

 favourable sections to display this fact, and it gave me much trouble to 

 make myself certain of it. The cells of the outer layer of the epithelium 

 of the gland are regularly columnar, and do not seem to be nucleated, 

 except in virgin pitchers. (Fig. 11.) When crushed between the cover 

 and the slide they do not seem to have fluid contents, but spread out as 

 if they had a putty-like consistency. The inner cells are larger, more 

 irregular, and have coloured nuclei. In a few cases I have seen 

 appearances as if the intercellular canals had direct communication with 

 the spiral tissue ; but the possibility of this being an optical illusion is 

 so considerable, that I could not venture to assert it as a conclusion. 

 There is, however, as great probability that such connection does exist 

 as there is in the view of the origin of the hepatic ducts advanced 

 by Chrzonsczsczewsky and others. Examination by high immersion 

 powers have convinced me that these intercellular canals are really 

 walled, and that they contain streams of colourless protoplasm, which is 

 in a state of slow movement. These glands vary very greatly in size in 

 different varieties of Nepenthes, the largest which I have seen being at 

 the bottom of a mature pitcher of N. distillatoria, which measured -375mm. 

 by -2, whilst the smallest were at the top of a virgin pitcher of 

 N. Rajjlcsiana, measuring only -045mm. (Fig. 12.) The rule of their 



