213 



male butterflies appeared, took hold of the chrysalis, as before, 

 but were easily frightened away. 



By six o'clock, same afternoon, the color had changed, and 

 males came freely, attached themselves firmly, and would not let 

 go, in fact, were utterly regardless of their safety. When picked 

 ofifthey would fly around and return at once. Two males re- 

 mained all night. Before daybreak next morning, I was at my 

 post, and there found the two males, opposite one another, head 

 down, abdomen curved toward the abdominal end of the chry- 

 salis, both apparently exercising a pressure. Lighted matches 

 held near them would not drive them off, shaking the twig did 

 not loosen their hold, only picking them off bodily separated 

 them from the chrysalis. The latter was now almost black, and 

 momentarily I expected the shell to burst. This happened, but 

 the break was not at the usual place. Owing probably to the 

 pressure or weight of the butterflies the shell burst at the abdom- 

 inal end, and instayitly one of the males made connection ivitJi the 

 female imago, while the head and thorax of the latter were still en- 

 closed in the sJiell. After about ten minutes, I determined to free 

 the new insect, which was accomplished by a slight pressure on the 

 shell, and I then removed the pair and suspended them, to a leaf- 

 stem. The wings of the female immediately began to expand, 

 but they did not fully develop. Without my aid, the imago 

 would not have been able to extricate itself from the shell, al- 

 though copulation had been affected. 



I suspended another chrysalis, well discolored, under same 

 conditions, October 7, in the morning. Males flocked around 

 the chrysalis, circled about a few times, approached closely 

 and then flew off again, none having alighted or actually touched 

 the chrysalis. This went on for an hour, when a male emerged. 

 The butterflies were mostly caught and all proved to be males. 



October 17, another chrysalis was suspended^under same con- 

 ditions as the last mentioned. Males appeared, etc. Behavior 

 just as before; none touching. The imago proved to be a male. 



It seems to me that the sexual odor is but faintly developed 

 when first discoloration takes place, and hence the chrysalis draws 

 the males but little, but as the color changes the odor developes 

 rapidly, so that males flock to the chrysalis from different direc- 

 tions." 



On November i, Dr. Wittfeld again writes, " To-day I made 

 another corroborative observation on Heliconia chrysalis. At 

 eight A. M. , 2 (5 (5 attached themselves to female chrysalis, and 

 acted as before reported. Four more males had appeared by nine 

 o'clock, took hold as best they could, and the six made quite a 

 bunch. Soon after others came, but had to be content with fly- 

 ing in close proximity, as there was no more holding room. At 

 ten o'clock, I freed the female from the crowd, and found the ab- 

 ■domen exposed, but head and thorax still in the shell. I observed 



