CATECHU 



1225 



CATERPILLAR 



of insects. Its plumage is a deep slate color 

 above and lighter below, with a reddish-brown 

 patch beneath the tail. In winter it migrates 

 to the extreme southern part of the United 

 States, or even to Mexico and Central 

 America. 



CATECHU, kat'echoo, a resinlike substance 

 used in tanning, dyeing, calico printing and 

 in medicine. It is obtained chiefly from the 

 wood of various acacia trees native to India, 



the best quality being the product of trees 

 about one foot in diameter. The bark is re- 

 moved for use in tanning, and the heartwood 

 is cut up into pieces and boiled in water until 

 a tarry substance results. After this has par- 

 tially hardened, rough blocks or balls of it are 

 wrapped in large leaves, and in this form it is 

 placed on the market. The neutral dyes which 

 this catechu, or cutch, produces are very val- 

 uable. In medicine it is a valuable astringent. 



, a wormlike creature 

 which bears somewhat the same relation to 

 a butterfly that an ugly, rough bulb bears to 

 a stately lily; for from this crawling thing, 

 which is to most people one of the most 

 loathsome of living objects, there develops in 

 time the most beautiful of all the insects 

 (see BUTTERFLY; MOTH). The curious name 

 probably means hairy cat; it thus would really 

 seem to belong to the woolly caterpillars only, 

 but it is applied as well to the hairless ones. 



The Story of a Caterpillar. Molting. When 

 the egg of a butterfly hatches, it is a tiny 

 caterpillar which crawls out ; and as the butter- 

 fly has taken care to place the egg near some 

 plant, it finds its food near at hand. At once 

 it begins to eat and to grow, but its skin does 

 not grow with it as does the skin of most 

 animals. Soon this becomes too tight, and the 

 caterpillar prepares to throw it off. A split 

 appears on the upper part, near the head end, 

 and the caterpillar then wriggles itself out, 

 appearing in a new soft skin which has been 

 folded in under the old one. This, too, is in 

 turn outgrown, and the process is repeated four 

 or five times before the caterpillar is fully 

 grown. In the temperate regions most species 

 remain in the caterpillar state for two or three 

 months, but in cold climates, where they pass 

 the winter in a condition of inactivity, longer 

 intervals elapse between successive molts. 

 Some species of the Arctic regions take from 

 two to three years to pass from the egg to 

 the butterfly state. 



Structure. A caterpillar 'has usually twelve 



rings or segments, not including the head, and 

 to each of the first three of these is attached a 

 pair of five-jointed legs. These develop later 

 into the legs of the perfect insect, but the 

 feet or leg-stumps on the abdomen are not 

 really legs and are shed with the last skin. 

 Occasionally, as in the so-called measuring 

 worm, there is but one pair of legs on the 

 abdomen, and the larva moves by drawing 

 these hind legs up to the front pair, thus form- 

 ing a loop or arch of its body. 



The head has six eye-spots on each side, a 

 pair of short, jointed feelers, by which the 

 caterpillar guides itself in moving, and strong, 

 biting jaws which are very different from the 

 sucking mouth-parts of the butterfly. The 

 body may be naked or covered with hairs, 

 bristles or spines, which in caterpillars living 

 an exposed life are often brightly colored. 

 On the skin of the hairless species there fre- 

 quently appear lines, eye-spots or ringed spots 

 of bright colors contrasting with that of the 

 body, and many a caterpillar might by reason 

 of its color be considered really beautiful if 

 it were not for its wormlike appearance. For 

 more details of the part played by the cater- 

 pillar in the development of a moth or butter- 

 fly, see articles on those insects. 



Protection. Like most living things, many 

 caterpillars have ways of protecting them- 

 selves from attack. Some of them make^nests 

 for themselves of rolled leaves or of spun 

 silk ; some burrow into plants. In some species 

 there are present glands which secrete an 

 unpleasant fluid, while with others it is a 



