306 Field, Forest, and Wayside Flowers 



pels them to carry it away with them to other 

 dogbane flowers, 



The fly-caller seems unable to sip the nectar 

 except by running his proboscis in between the 

 long anthers, and just above the horny excres- 

 cences on the corolla. When he attempts to with- 

 draw, after drinking his fill, the three points lock 

 together, like the jaws of a trap, holding the tip 

 of his proboscis in durance vile. If the winged 

 captive is big and strong, he gets free with a 

 long and a vigorous pull. But small flies are 

 often held prisoners till they die, probably from 

 starvation. Sometimes one may see three or four 

 of these hapless victims on one full-blooming plant 

 of spreading dogbane. 



Among the prisoners one may often see a little 

 summer-fly of dudish aspect, with body ringed 

 with alternate bands of bronze and gold and wings 

 of gauze shot with opaline colors. To what end 

 is this bright little fellow sacrificed ? Held as he 

 is by the tip of his proboscis, his body does not 

 come into contact with the plant, and hence it can- 

 not be digested by the vegetable juices, as are the 

 corpses of the sundew's victims. The only possi- 

 ble justification the dogbane can furnish for his 

 taking off is that he has trespassed upon the 



