SILK-WORM GUT. 107 



collect the fully grown larvae just before they are ready to 

 spin their cocoons, as they are quite plentiful in the central 

 portions of the United States, especially in button bush or 

 water-sycamore swamps. In order to enable any one to 

 identify the moths and their larvae, the following good de- 

 scriptions are abridged from C. H. Fernald ( u Standard 

 Natural History," S. E. Cassino & Co., Boston, 1884, vol. 

 ii, pp. 456-457) : 



The Cecropia silk- worm, Platysamia cecropia, which has 

 a wide distribution in the United States is one of our largest 

 moths, expanding six inches or more. It has a most re- 

 markable appetite, feeding on no less than fifty different 

 species of plants, among which are the apple, plum, maple, 

 elm, oak, beech, birch, willow, etc. The female lays from 

 two to three hundred eggs, which are creamy- white and 

 striped with reddish, and hatch in eight or ten days. The 

 young caterpillars are black, and change in color and size at 

 each moult until mature, when they are three or four inches 

 long, and of a pale green, or bluish-green color. The tu- 

 bercles on the third and fourth segments are coral red ; the 

 others on the back are yellow, except those on the second 

 and last segments, which, with those along the sides, are 

 blue ; and all are more or less armed with black bristles. 

 They construct elongated, coarse, dull brown cocoons. The 

 wings of the moth are of a rich brown color, sprinkled with 

 gray scales, with a large kidney- shaped spot, shaded more 

 or less with red, and margined with black, near the middle 

 of each wing. A red band, edged on the inside with white, 

 crosses the wings near the middle. The outer edges of the 

 wings are pale silky brown, through which runs an irregular 

 black line on the fore wings, and a double broken band on 

 the hind ones. The base of the fore wings is dull red, with 



