OF ARTS AND SCIENCES. 59 



Larva, Stage I. — Length when first hatched (June 15), 6 to 7 mm. 

 On emerging from the egg the larva is mostly black, the head, body, 

 and hairs are jet-black, but the tubercles are pale yellowish green, the 

 hairs or bristles they bear being black ; the abdominal legs also are 

 pale, the thoracic ones black ; shortly after emerging the larva turns 

 entirely black. One larva was observed drawing itself slowly out of 

 the hole it had gnawed in the egg, having eaten its way through the 

 egg-shell at 11.30 A. m., June 15. It was mostly black, but the pale 

 yellowish green tubercles were flattened down close to the body, and 

 the hairs or setae in each verticil or pencil were united in one pencil- 

 like mass and bent to one side on the body. The abdominal legs were 

 pale livid, the thoracic ones black. In ten minutes more the tubercles 

 had become erect, higher and longer (probably swelled out by the 

 presence of the blood), and by this time the hairs had assumed their 

 radiate arrangement. 



In one or two minutes more, viz. from 11 to 12 minutes after ex- 

 tricating itself from the egg, the tubercles had all become of full length, 

 and erect, and the black setse, or hairs, had now spread out in a ver- 

 ticillate way, as normal. In an hour more the larva had turned per- 

 ceptibly darker, and in three quarters of an hour more it had turned 

 entirely black. The spiracles, however, are yellowish green, and thus 

 are rather conspicuous. The body is stout and thick, the head is as 

 wide as the body. On the prothoracic segment are four dorsal tuber- 

 cles, two on each side of the median line. Along the body are six 

 rows of tubercles, each usually bearing about five radiating setae ; those 

 of the two dorsal series are larger than the subdorsal ones. The tuber- 

 cles are rather short and stout, fleshy ; and are one half to two thirds 

 as long as the bristles. The latter are stout, taper to the end, which 

 under a half-inch objective is seen to be blunt, slightly bulbous, and 

 clear, so that these setfe are evidently glandular in function ; they are 

 slightly rough with rudimentary spinules. On the 8th abdominal 

 segment, instead of two tubercles, one on each side of the median line, 

 as on abdominal segments 1 to 7, there is a single median tubercle, 

 about twice as large round as those on each side, though no higher, 

 and it is evidently the result of the concrescence in the embryo stage 

 of two tubercles, such as are to be seen on the segments in front. It 

 is transversely broad at base, and also bears eight or ten setoe, or 

 nearly twice as many as the homologous tubercles on the other seg- 

 ments. The thoracic feet bear at their tips three lancet-shaped flat- 

 tened acute tenant hairs ; while the abdominal legs bear about 16 

 crotchets. 



