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thereby, and the instant the tail is fre'ed from the sheath of skin, 

 the chrysalis will be seen to rise, the last segment describing an 

 arc of a circle of which the ligament is the radius, and the 

 tail, now bent forward, will be brought around and over the 

 packet of skin and will strike the silk. It has been suggested 

 to me that this membrane or ligament may be the drawn out 

 rectum, or the external cover of the rectum, and further ob- 

 servations may sustain that view. At present I know it 

 only as a ligament binding the chrysalis to the old skin, as 

 it appears to the eye. I have given a full account of the 

 observations made by me on this pupation in a paper written 

 for the Canadian Entomologist, but which has not yet been 

 published, and therefore I repeat only so much here as will 

 serve to make the history of D. archippus more complete. 



The larva of D. archippus spins a button of white silk when 

 preparing for its pupation, and after fastening therein the hook- 

 lets of its anal claspers, soon casts off, and hangs suspended, at 

 first in the form of an oval, the head being brought up to the 

 twelfth segment. A few hours later the body relaxes and the 

 position becomes that of a figure (j. Still later it hang^ 

 straight down, the four anterior segments bent at a right angle 

 to the body. When this position is reached it is evident that 

 the final change is not far off. Soon a spasm of contraction 

 will be seen, the body being lifted up to the last segment and 

 let fall again. This is repeated more than once after short in- 

 tervals, and is followed by a slight creeping movement of the 

 body beneath the skin, advancing from the last segment forward. 

 This movement increases in rapidity and intensity, and as the 

 strain on the anterior segments becomes severe, the skin bursts 

 on the dorsal line of the second, third and fourth segments, and 

 the top of the head is also rent. The mesonotum of the chrys- 

 alis is first forced through, and the body is slowly divested by 

 the continued creeping movement. The slit is oblique and the 

 ventral side is at first covered by the skin three segments be- 

 yond the dorsal, the skin fitting tightly everywhere, except on 

 the last segment, where it is loosening and gathering in a mass 

 about the anal feet. When the dorsum is exposed at the tenth 

 segment the ventral is covered at the eighth, and the effort for 



