﻿NORTH AMERICAN SPHINGIDiE. 121 



in circles on the surface with which it may come in contact, with its head downwards. 

 For a long while I supposed this was a mere expression of pain, until I experimented 

 in various ways with this instrument, for the purpose of ascertaining its function. 



My first experiments consisted in the excision of the antennae, immediately above 

 the bulb, in the male Samia Cecropia, as soon as it had escaped from the cocoon, and 

 before expansion of the wings had begun. The circulating fluids exuded, and soon 

 formed over the cut surface, a clot by which it was permanently closed. There was no 

 escape of air from the severed tracheal trunk, nor any indications of respiratory effort 

 on the part of the imago, neither was the globule of fluid taken up through the 

 tracheal trunk. The mutilation gives rise to very little expression of pain, after the 

 first shock of the operation, and the imago fixes itself as usual to expand its wings, 

 expansion taking place as completely as in the unmutilated specimen. On the 

 approach of night the mutilated male makes no voluntary effort to use his wings. 

 He is gentle and docile, and permits himself to be handled without betraying a desire 

 to escape, or any sense of danger. If at this time, one endeavors to compel him to 

 fly, he agitates his wings with a trembling motion ; and if thrown into the air, uses 

 them so ineffectually as not to break the force of his fall, or so as to precipitate him 

 head foremost to the earth with a shock that appears to benumb him. By persistence 

 he is at last, perhaps, driven to use the organs of flight ; but whilst employing them 

 with vigor, his position is reversed in mid-air, and he descends to the earth, vainly 

 endeavoring to change it or arrest his fall ; or he dashes himself with violence against 

 some obstacle, thus bringing his flight to a sudden conclusion. The 'power to hover 

 has been completely lost. After a few efforts of this kind, it becomes almost impossible 

 to compel a mutilated specimen to attempt flight. It will remain fixed in one place, 

 for two or three days, and at the end of that time may make a voluntary effort to use 

 its wings. The irregularity, not to say the madness of its flight, is no less observable 

 than in the beginning. Under these circumstances, one of my specimens escaped 

 into the open air from my study in daylight. After extricating himself from 

 amongst the branches of a tree standing near the door, he arose into the air in a spiral 

 tract, around which he ascended until attaining a height at which he was almost lost 

 to sight. Here he maintained himself by sailing on his wings until I lost sight of 

 him by intervening houses. But, though I placed myself quickly in a position to see 

 him again, he was no where visible, and must have descended suddenly from mid-air. 



The males of the same species, taken by what is called pairing, in full possession 

 of all their powers and instincts, and animated especially by the sexual, are strongly 

 attracted by light. If the light in a room be so guarded that the specimen cannot 

 injure itself, and a perfect male be held by the thumb and fingers beneath the wings 

 and thrown with force in a direct line from the light, the individual, by the use of 

 the wings will arrest himself as the force of the impulsion diminishes, and reversing 



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