LEPIDOPTERA. 211 



secure themselves by a transverse band, as well as by the tail, 

 previously to their transformation to chrysalids ; and the latter are 

 angular. All these characters exist in the following species. 



In the month of June, there may be found, on the leaves of the 

 parsley and carrot, certain caterpillars, more commonly called pars- 

 ley-worms, which are somewhat swelled towards the forepart of 

 the body, but taper a little behind. When first hatched, they are 

 less than one tenth of an inch in length, are of a black color, with a 

 broad white band across the middle, and another on the tail ; and 

 the back is studded with little black projecting points. After they 

 have increased in size and have cast their coats, it is found that 

 the white band covers only the sixth and seventh segments, that 

 the black projecting points spring from spots of an orange color, 

 and on the lower part of the sides is a row of white spots, two 

 more spots of the same color on the top of the first segment, and 

 one larger spot on the tail. These caterpillars alter in color and 

 appearance with each successive moulting, and, before they are 

 half grown, the projecting points and the white band and spots en- 

 tirely disappear, the skin becomes perfectly smooth and of a deli- 

 cate apple-green color, rather paler at the sides of the body, and 

 whitish beneath, and on each segment there is a transverse band 

 consisting of black and yellow spots alternately arranged. When 

 touched, they thrust forth, from a slit in the first segment of the 

 body just behind the head, a pair of soft orange-colored horns, 

 growing together at the bottom, and somewhat like the letter Y 

 in form. The horns are scent-organs, and give out a strong and 

 disagreeable smell, perceptible at some distance, and seem to be 

 designed to defend the caterpillars from the annoying attacks of 

 flies and ichneumons. These caterpillars usually come to their 

 full size between the tenth and twentieth of July, and then meas- 

 ure about one inch and a half in length. After this, they leave off 

 eating, desert the plants, and each one seeks some sheltered spot, 

 such as the side of a building or fence, or the trunk of a tree, 

 where it prepares for its transformation. It first spins a little web 

 or tuft of silk against the surface whereon it is resting, and en- 

 tangles the hooks of its hindmost feet in it, so as to fix them se- 

 curely to the spot ; it then proceeds to make a loop or girth of 

 many silken threads bent into the form of the letter U, the ends 



