SIDE-SADDLE FLOWERS. 75 



sufficient!)- strong to support itself, but falls. The 

 inability of insects to crawl up against the points of 

 the hairs I have often tested in the most satisfactory 

 manner."^ 



The annexed figure represents the pitchers of the 

 species to which these observations refer (fig. 7). It 

 is also that on which many subsequent and confirma- 

 tory experiments were made. 



The tissues of the internal, or lining, surfaces of the 

 pitchers in Sarracenia are not identical in all the 

 species. In some, and probably most, there are four 

 kinds of surfaces, proceeding from the mouth down- 

 w^ards to the bottom of the tube. First, there is 

 an attractive surface, often brightly coloured, A\'hich 

 occupies the inner face of the lid, and this, in common 

 with the mouth of the pitcher, is covered with minute 

 honey-secreting glands. Then, secondly, there is a 

 conducting surface of glassy cells, which are elon- 

 gated into conical processes overlapping each other, 

 like the tiles of a house, so as to afford no foothold 

 for an insect attempting to crawl up again. This is 

 succeeded by a large granular surface, which is 

 smooth and polished so as to afford no foothold. 

 And, finally, there is a detentive surface, which 

 occupies the lower part of the pitcher. It is studded 



^ Dr. James McBride in " Transactions of the Linntean 

 Society," vol. xii. 



