The Ameeicax Pitchee-Plaxts 111 



tlie plant. Late in the snmmer the tubes are usually half filled with 

 dead insects of many species, which have been lured thither by the 

 bright colors of the hoods, or a sugary secretion on the outside of the 

 tubes, or both. Just within the mouth of the tube the surface is so 

 smooth that it affords a very insecure foothold, and a little farther 

 down is a close array of stiff hairs pointing downward, which make 

 descent very easy and ascent by crawling almost impossible. And 

 the tube is usually too narrow for an insect of any size to fly out after 

 it once gets inside. The function of the ^'windows" in the over- 

 arching hoods is now evident, for flying insects as a rule do not like 

 to* enter dark places. Once within the zone of downward-pointing 

 hairs, death by drowning is almost inevitable ; and human ingenuity 

 could hardly devise a better fly-trap than a pitcher-plant leaf. 



There are, however, a few species of insects which in the course of 

 ages have learned to circumvent these elaborate pitfalls and even to 

 profit by the misfortune of their less wary fellow-creatures. In 

 many of the leaves can be found one or more larvae feeding on the 

 carcasses, and these when the proper stage in their development arrives 

 escape by gnawing their way out, or perhaps in some cases by flying. 

 Occasionally a spider spins its web across the tube and robs the plant 

 of some of its prey. Or when there is more water than insects 

 mos(|uitoes may use these natural pitchers for breeding-phices. 



There has been some diftercnce of opinion as to whether the pitcher- 

 plants actually digest the insects entrapped in their leaves ; and doubt- 

 less the digestive action is less easily demonstrated in some species 

 than in others, and may take place only during a brief period of the 

 year. But the conclusion is irresistible that such highly specialized 

 contrivances must be of some advantage to the plant, and when the 

 leaves finally decay the insect remains in them must contribute in no 

 small degree to the nutrition of the plants through their roots, if 

 nothing else. 



The flowers of nil the si)ecies are rather showy and more or less 

 odorous, but last only two or three weeks, and only a minority of the 

 ])lants in a given area seem to bloom in any one year. In the South 

 American species there are several flowers on one stalk, but iu the 



