Joimml of the progress of Silk JVorms. 267 



cocoons smoked u ith brimstone in the morning, remained 

 in the tub till the following^ one. In spreading them out 

 to the sun in order to dry the larvas, I was surprised to 

 find that many butterflies had come out. Not a single 

 one was discovered among the cocoons of the first pick- 

 ing, which immediately after the fumigation were exposed 

 to a burning sun. From this I may infer, that the brim- 

 stone smoking has litde or no effect in killing the larvae, 

 and that the heat of the sun's rays does it effectually. In 

 proof of this, I can assert that the few butterflies \\hicl-i 

 made their appearance on the second picking, died ver} 

 soon after their exposure to the sun. 



tual mode of killing the chrysalis, is to bake tlie cocoons in nw 

 oven, made pretty warm, but not so hot as to scorch when tried 

 with a sprinkling of flower. If the oven be not warm enough, 

 instead of killing the chrysalis, it will only bring them forward 

 the sooner. So it is with fumigations of brimstone : hence Mr, 

 Busti's method not being effectual, the flies were hastened 

 through the cocoons. S. Alexander, 



