322 



Haiidbook of Nature-Study 



alone. There is another butterfly cahed the viceroy, which has taken 



advantage of this immunity from bird attack on the part of the monarch 



and has imitated its colors in a truly remarkable way, differing from 



it only in being smaUer in size and having a black band across the 



middle of the hind wing. (See The Ways of the Six Footed, "A Sheep 



in Wolf's Clothing"). 



The milkweed caterpillar, which is the young of the monarch butterfly, 



is a striking object, and when fully grown is about two inches long. The 



milkweed is a succulent food and the caterpillar may mature in eleven 



days; it is a gay creature, with ground 



color of green and cross stripes of 



yellow and black. On top of the 



second segment, back of the head, are 



two long, slender whiplash-like organs, 



and on the seventh segment of the 



abdomen is a similar pair. When 



the caterpillar is frightened, the whip- 

 lashes at the front of the body twitch 



excitedly; when it walks, they move 



back and forth. Those at the rear of 



the body are more quiet and not so 



expressive of caterpillar emotions. 



These filaments are undoubtedly of 



use in frightening away the little 



parasitic flies, that lay their eggs upon 



the backs of caterpillars; these eggs 



hatch into little grubs that feed upon 



the internal fatty portions of the 



caterpillar and bring about its death 



through weakness. I remember well 



when I was a child, the creepy feeling 



with which I beheld these black and 



yellow-ringed caterpillars waving and 



lashing their whips back and forth after I had disturbed them; if the 



ichneumon flies were as frightened as I, the caterpillars were surely safe. 

 The caterpillar will feed upon no plant except milkweed; it feeds both 



day and night, with intervals of rest, and when resting, hides beneath the 



leaf. Its striking colors undoubtedly defend it from birds, because it is 

 as distasteful to them as is the butterfly. However, 

 when frightened, these caterpillars fall to the ground 

 where their stripes make them very inconspicuous 

 among the grass and thus perhaps save them from 

 the attack of animals less fastidious than birds. 

 These caterpillars, like all others, grow by shedding 

 the skeleton skin as often as it becomes too tight. 



The monarch chrysalis is, I maintain, the most 

 beautiful gem in Nature's jewel casket; it is an oblong 

 jewel of jade, darker at the upper end and shading -"o 

 the most exquisite whitish green below; outlining thii 

 lower paler portion are shining flecks of- gold. If we 

 look at these gold flecks with a lens, we cannot but 

 believe that they are bits of polished gold-foil. There 



The monarch caterpillar. 



Photo by M. V. Slingerland. 



Monarch chrysalis. 



A jewel of living jade 

 and gold. 



