8 



CATERPILLAR 



CATGUT 



done in elucidating the rdle of colour in the con- 

 stitution of these and other animals. 



General Life. As already noted, most cater- 

 pillars lead an active life, some roving only at 

 night, others -also in the daytime. Young larvge 

 have been observed to seek the light. Their move- 

 ments are guided by an appreciation of the force of 

 gravitation ; they usually crawl upwards ; and they 

 always know their food-plant when they come to 

 it. Their frequent falls from, for them, considerable ' 

 heights, are broken, it has been suggested, by the 

 springy hairs with which they are so often covered. 

 Many of them seem to have an insatiable hunger, 

 and eat straight on. Their ravages among vege- 

 tables and other plants are only too well known. 

 Some forms are carnivorous, and Mr Poulton has 

 suggested that this might arise from cannibalism 

 induced by scarcity of food, as his observations 

 vividly indicate. While older larvae will appar- 

 ently rather starve than take to a new food-plant, 

 it has been conclusively shown that the newly 

 hatched larva is not so fastidious, but 'is free to 

 form special relations with occasional or rare food- 

 plants. Trouvelot's experiments on the larvae of 

 Polyphemus showed that a caterpillar, fifty-six 

 days old, had consumed not less than one hundred 

 and twenty oak leaves, weighing in all three- 

 fourths of a pound, and had drunk not less than 

 half an ounce of water. The food would weigh 

 86,000 times the original weight of the larva. ' Of 

 this, about one-fourth of a pound becomes ex- 

 crementitious matter ; 207 grains are assimilated, 

 and over five ounces evaporated.' A few larvae 

 ( Nymphula, &c. ) are aquatic, many bore in wood, 

 leaves, and soft vegetable substances, others are 

 largely subterranean. 



The caterpillars of some of the silkworm sub- 

 order (Bombycina) live together within a common 

 pouch-like cradle, and others move in file-like 

 processions (see ARMY-WORM). Migrating cater- 

 pillars (Noctua) have been described, which move 

 in search of food in vast armies, marching straight 

 on over everything, until a fit pasturage is found. 

 In one case ( quoted by Kirby and Spence from the 

 Charleston Courier, May 1842) the passage of such 

 a host is said to have made the ground black for 

 days ; in another instance reported from America, 

 they stopped a heavy train going at the rate of 10 

 or 12 miles an hour. 



Comparatively few caterpillars reach maturity 

 ( happily for the sake of the plants in the next 

 season ) ; many are destroyed by the weather, 

 many by hungry birds, reptiles, and other animals, 

 and many by insect pests of the families Ichneu- 

 monidae (see Art. ICHNEUMON) and Tachinariae. 

 The ichneumon flies pierce the caterpillars, and 

 make them the receptacles of their eggs and the 

 edible cradles of their larvae. 



As typical injurious caterpillars may be noticed, 

 ( 1 ) on vegetables, those of the cabbage-moths (e.g. 

 Mamestra brassicce, and several species of Pieris 

 or Pontia), the turnip-moths (Noctua segetum, 

 Cerostoma xylostella), the silver Y-moth (Plusia 

 gamma), the carrot-moths (Depressaria), the hop- 

 moths (Dasychira, Hepialus, Pyralis), the pea- 

 moth (Grapholitha pisana), the death's-head 

 (Sphinxatropos) ; (2) on trees, those of the goat- 

 moth (Cossus ligniperda), the wood leopard-moth 

 (Zeuzera cesculi), the buff- tip moth (Pygcera 

 bucephala), the lackey-moth (Bombyx (clisio- 

 campa ) neustria ), &c. See Miss Ormerod's Injuri- 

 ous Insects. 



The devastations of caterpillars are to^some 

 extent compensated for by the fertilising work 

 of the adults, and by the silk of the silkworms. 

 But apart from their destructiveness and utility, 

 they are full of interest and of scientific puzzles. 

 Old Swamnierdam saw in their metamorphosis 



' the resurrection painted before our eyes,' w) ile? 

 moralists and poets have often delighted in point- 

 ing out the analogies suggested t>y the crawl- 

 ing immature caterpillar, with faint promise of its- 

 future, by the seeming death and coffin-like cocoon 

 of the chrysalids, by the new birth, glory, and 

 heavenward flight of the perfected forms. 



LITERATURE. Balfour, Embryology, voL i. ; Kirby and 

 Spence, Introduction to Entomology ; Lubbock, Metamor- 

 phoses of Insects ('Nature' series); Packard, Guide to the 

 Study of Insects ; Poulton, Transactions of Entomological 

 Society (1885-6-7), British Association Report (1887), 

 Proceedings of Zoological Society (1887); Wallace, Pro- 

 ceedings of Entomological Society (1867); Weismann 

 (translated by Meldola), Studies in the Theory of Descent 

 (1880-82); Wilson, Larvce of British Lepidoptera and 

 their Food Plants (London, 1880). 



Catesby, MARK, naturalist, born about 1679, 

 probably in London, travelled in North America in 

 1710-19 and 1722-26, and published Natural His- 

 tory of Carolina, Florida, and the Bahama Islands 

 (2 vols. 1731-43), Hortus Britanno-Americanus, and 

 a work on the fishes, reptiles, and insects of the 

 Isle of Providence. German translations of the 

 first and last appeared at Nuremberg. He died in 

 London, 23d December 1749. 



Catesby, ROBERT, born in 1573, was a. 

 Northamptonshire Catholic of good fortune and 

 lineage, being sixth in descent from Richard III.'s 

 Catesby, who was hanged three days after Bos- 

 worth. Robert, however, had suffered much.as a 

 recusant both by fines and imprisonment, when 

 in 1604 he engaged in the Gunpowder Plot (q.v. ). 

 He was shot dead in the defence of Holbeache 

 House, 8th November 1605. 



Cat-fish, in Britain, is usually a name for the 

 Wolf-fish (q.v.). In America the name is com- 

 monly applied to a very different fish, one of the 

 genus Pimelodus and family Siluridae. Sixteen 

 species occur in the lakes and rivers of North 

 America. The skin is naked, and the head has 

 eight fleshy barbules. The Common Cat-fish (P. 

 atrarius), or Horned Pout, is one of the commonest 

 river fishes of the United States, especially in the 

 east and north. It is from 7 to 9 inches in length, 

 and is a very important food fish, though its flesh, 

 like that of all the cat-fishes, is insipid. Like all 

 its congeners it prefers muddy bottoms, and is 

 sluggish in its movements. The Great Lake Cat- 

 fish ( P. nigricans ) is from 2 to 4 feet long, weighs 

 from 6 to 30 pounds, and is found in lakes Erie 

 and Ontario. 



Catgllt is employed in the fabrication of the- 

 strings of violins, harps, guitars, and other musical 

 instruments ; as also in the cords used by clock- 

 makers, in the bows of archers, and in whipcord. 

 It is generally prepared from the intestines of the 

 sheep, rarely from those of the horse, ass, or mule, 

 and not those of the cat. The first stage in the 

 operation is the thorough cleansing or the in- 

 testines from adherent feculent and fatty matters ; 

 after which they are steeped in water for several 

 days, so as to loosen the external membrane, which 

 can then be removed by scraping with a blunt 

 knife. The material which is thus scraped off is 

 employed for the cords of battledoors and rackets, 

 and also as thread in sewing the ends of intestines 

 together. The scraped intestines are then steeped 

 in water, and scraped again, when the large in- 

 testines are cut oft' and placed in tubs with salt, 

 to preserve them for the sausage-maker ; and the 

 smaller intestines are steeped in water, thereafter 

 treated with a dilute solution of alkali ( 4 oz. potash, 

 4 oz. carbonate of potash, and 3 to 4 gallons of 

 water, with occasionally a little alum), and are 

 lastly drawn through a perforated brass thimble, 

 and assorted into their respective sizes. In order 

 to destroy any adherent matter which would lead. 



