NOTES ON THE NErENTITACEiE, OR PITCHER-PLANTS. 307 



longer than if not so supplied. This I regard as 

 the primary object of the foliaceous extension. 



In their native swamps they are always replen- 

 ished at night so that they may be able to undergo 

 the effects of the heat to which they are subjected 

 during the day. In our own country during summer 

 we find it much better to water plants at night, so 

 that they may be able to stand the heat of the 

 following day without showing any signs of exhaus- 

 tion. If this operation be left over till the morning 

 it is not nearly so effective, as the plants suffer 

 from the heat of the sun before they have had 

 time to assimilate the amount of moisture necessary 

 for their support. The pitcher-like leaf of this genus 

 is a beautiful illustration of how a plant adapts itself 

 to its environment. 



According to some authorities, the purpose served 

 by the lid is " for keeping the moisture that is stored 

 at night from evaporating during the day, as the 

 lid closes under the influence of the sun." This 

 must be regarded as one of the many exploded 

 fables related of the pitcher-plant. It should be 

 quite evident to anyone who has examined a pitcher 

 that the lid, after having been fully developed, 

 could never close again, no matter to what degree 

 of heat it might be subjected, whether by the sun's 

 rays or from artificial application. In plant-stoves, 

 where they are successfully cultivated, the tempera- 

 ture ranges from 65° to 85° F. with sun heat. 



A very common belief is that the pitchers are the 

 flowers ; but the inflorescence is inconspicuous, 

 and when fully expanded is of a greenish colour, 

 gradually becoming brown, and remaining a long 

 time in perfection. The flowers are dioecious, and 

 it seldom happens that plants of the different sexes 

 can be got in flower at the same time. This fact, 

 as well as the very great preponderance of plants 

 with male or pollen-bearing flowers, may account in 

 a large measure for the comparative scarcity of 

 new species, in view of the long period that has 



