BLUE HrXTFU-.SS 4:j-} 



tweeu the toj) and bottom of tlif clianibtT. J.atci-, upon this 

 preh'iiiinarv support, a neat tubuhir cocoon is spun. It is 

 rounded at both ends, grayish yellow in color, glossy and 

 rather transparent. It measures eight by seventeen milli- 

 meters, and only ])artly fills the roomy cell. As a final touch 

 the interior is lightly coated with a pale, smooth varnish. 

 The cocoon is finished in two days, after which the larva ex- 

 cretes a mass of waste matter in one end. This accomplished, 

 it lies quietly awaiting pupation, which follows in eight days. 



The pupa is ycllowisli white and beautifully folded so 

 tliat its remarkably long posterior legs do not extend beyond 

 the tip of its abdomen. Its head is armed with four spikes; 

 u2)on either side of four of the six abdominal segments there 

 is a "jack," or protruding T-shaj^ed support, and protruding 

 from opposite sides of the lateral segment is a pair of club- 

 shaped appendages. (Fig. 140.) 



At first I took these strange objects to be the remains 

 of ancestral legs. I thought them inherited rather than ac- 

 quired characters, but continued observation of the pupa 

 within its cocoon proved the contrary. They have been ac- 

 quired in order that the insect's heavy abdomen may be 

 kept level or centered within the cocoon, no matter how it 

 is shaken about or turns of its own accord. This is very im- 

 portant to the insect. It is not that the pupa would be in- 

 jured by contact with the cocoon wall, but rather that the 

 weight of its own abdomen which is joined to the remainder 

 of its body bv a very narrow waist, would have to be borne 

 by the creature's tender legs. In such a case they would 

 become partly crushed and, owing to their great delicacy at 

 this period, would not develop properly. When the legs 

 become strong and have received their steel-blue pigment, 

 all the supporting appendages shrivel and are completely 

 lost. This takes place three days before the huntress emerges 

 from her cocoon. The supports are inflated with a watery 

 fluid which disappears as soon as a breach occurs in the pupal 

 skin. One may be cut off without seriously injuring the 



