I Pitcher Plants 7 



ever, at present " impracticable," i.e. remains a problem 

 for the experimental physiologist. Yet even the natural 

 selectionist most satisfied with accounting for the change 

 on the principle of the mechanically improving fly-trap is 

 notwithstanding the very man empirically to help, if not 

 anticipate us, by finding us a seedling varying in the 

 required direction among a patch of young Sarracenia ; 

 for on this and its offspring the experimentalist might best 

 begin. All such experimental researches are as yet only 

 in their infancy, but it is becoming admitted on all hands 

 that as the past of the science lies mainly in systematic 

 collections, in anatomical and microscopic analyses, so its 

 future has to be sought in the physiological laboratory, the 

 greenhouse, and the garden. 



Insect-Catching. — But how, the active minded observer 

 will ask, does our curious helmet-like Darlingtonia pitcher 

 keep its victims, — for though it is natural for an insect to 

 creep into what doubtless appears to it a very inviting new 

 kind of flower, why should it not creep out again ? A 

 first difficulty is afforded by the incurved margins ; but this 

 would not be enough to detain it ; and here comes in the 

 use of the relatively widely distended helmet-space with its 

 innumerable transparent glassy panes let into its whole 

 upper surface. The insect has eyes on the top and sides of 

 its head, and sees abundant light above to spread its wings 

 and beat itself upon the resisting roof and walls of the 

 pitcher as persistently and as vainly as he does within our own 

 window-casement. No doubt when he becomes tired and 

 falls down over the entrance he may at times escape, but 

 is more likely only to rest over it till he can again begin 

 his struggles on the wing, while the adjacent opening, 

 that of the fatal oubliette, is not only of much larger 

 diameter, but of gently -sloping sides instead of repellent 

 recurved margins. The walls of the leaf-tube substantially 



