THE CANADIAN ENTOMOLOGIST. 353 



from 73 mm. contracted to 84 mm. when in motion. At this stage the 

 segments were exactly the colour of the under surface of the leaves of 

 Sa/ix alba, a light gray-green. Otherwise there was no change. On the 

 thirty-second day the only change noticed was that two of the larvse 

 stopped feeding, emptied their intestines of a very dark viscous fluid, and 

 began to wander around the jars in which they were confined. On the 

 thirty-third day, at 11 a.m., one of these began to spin, and at 7.30 p.m. 

 the other did the same. On the thirty-fourth day the remainder of the 

 larvie, with one exception, fed ravenously, and on the thirty-fifth day one 

 more cocoon was found in the jar. This cocoon seemed very much 

 lighter in colour than the other two, possibly owing to its being spun on a 

 white handkerchief, instead of directly on the side of the jar, as in the case 

 of the other two. At this time the remaining larvae were clear pea-green, 

 with a slight bluish tinge dorsally ; otherwise the colour was -unchanged. 



On the afternoon of the thirty-sixth day another of the larv?e began 

 to spin, but the rest of the lot kept on feeding. The one spinning did not 

 empty its intestines, nor did it wander around the jar. On the thirty- 

 . seventh day another cocoon was found, and the remaining larvae all showed 

 signs of spinning, with the exception of one. Another cocoon was found 

 on the thirty-seventh day, and still another on the thirty-eighth. One 

 larva died from no apparent cause, as it simply refused to feed and 

 gradually shrivelled up. This larva was examined carefully with a glass, 

 but showed no signs of being parasitized ; the only peculiar thing noted 

 was that it v/as continually passing a clear watery fluid, and no regular 

 "balled" frass. 



The cocoons which were spun directly on the glass of the jars were 

 very free of the silvery threads so characteristic of Columbia, the silver- 

 silk being apparently used up in making a mat on which to construct the 

 cocoon. This mat, stretched over a space of about 4}^ inches by 2^ 

 inches, was very loosely laid at the outer margin, but next to the cocoon 

 was quite dense. Those cocoons formed on the twigs provided for the 

 purpose were a strong reddish-brown colour, with streaks and patches of 

 silvery-silk distributed over the surface of the cocoon. The inner cocoon 

 was of very close texture, much like parchment, and of a rather light 

 coffee colour ; very different from the inner cocoon of Cecropia, which is 

 very fluffy and of a light straw colour. The size of the cocoon is as 

 follows : Length from 2 to 2^ inches ; thickness from i^ to 2^ inches. 

 It was rounded at one end and drawn out to a point at the other, with the 

 effect of a valve at the pointed end ; the inner cocoon was egg-shaped. 



