COLOR IN FLOWERING PLANTS. 83 



are resorted to. Most insect-like orchids resemble brilliant but- 

 terflies, which, are as a rule unpalatable, and therefore enjoy com- 

 parative immunity from attack. May not the flowers be protected 

 by the resemblance, as the defenseless butterflies discovered by 

 Wallace are ? Some such reason as this makes it more easy to 

 comprehend the need of such elaborate development for which 

 adaptation to small flies or bees, as in the case of lady-slippers, is 

 hardly a satisfactory explanation. Nature is too economical to 

 spend so lavishly for the accomplishment of what has been done 

 much more simply in other ways. The desirability of combined 

 attraction and repulsion brings with it the need of many new 

 wiles. If "all things are fair in love and war," much may be 

 expected of a man or flower engaged at the same time in both 

 pursuits. 



Another orchid (Pogonia ophiogJossoides) is very difficult to 

 find because of its great likeness to the much more abundant In- 

 dian cucumber which lives in the same places. In company with 

 two botanists and a gardener well versed in the ways of the 

 woods, I have spent hours in finding half a dozen specimens. Mr. 

 Gibson, too, met with the same difficulty, actually treading the 

 orchid under foot, "the imitative whorled foliage of the medeolas 

 having beguiled my discrimination." Surely, though, it is the 

 pogonia which is the imitator. It is the rare form, fulfilling all 

 the conditions of mimicry. The two plants dwell together. The 

 rare one differs from its allies ; there is no other pogonia, and, in- 

 deed, no other orchid of our flora which has its leaves whorled on 

 the stem. The whole appearance of the plant is decidedly non- 

 orchidean, and, so far as pressed specimens show, the flower 

 continues the imitation, for the greatly elongated sepals and 

 three-parted corolla — all green — have decidedly the semblance of 

 the second whorl of leaves always found on the flowering stems 

 of the medeola. 



V. Alluring Color. — Color is sometimes a trap. 



There is a singular class of beings, half animal, half plant, in 

 their ways of living — a fascinating, uncanny sisterhood — the in- 

 sectivorous plants, which display marvelous ingenuity in the 

 entrapping of their victims. 



The bladder- wort, which abounds in stagnant ditches or ponds, 

 is a member of this class, which has no apj^arent attractive 

 powers. Yet Darwin says that one species has wonderfully con- 

 structed bladders, curiously like an entomostracan crustacean, 

 and, strangely enough, these are the very animals most fre- 

 quently killed by them. 



Pitcher-plants excited the interest of scientists and travelers 

 over a century ago, but the meaning and mechanism of these 

 " plant-saloons " was only discovered within comparatively recent 



