CATERPILLAR 



in philosophy, the highest classes 

 under which objects of knowledge can be syste- 

 matically arranged, understood as an attempt at a 

 comprehensive classification of all that exists. The 

 name has come down to us from Aristotle, in whose 

 a the categories are ten in number: Sub- 

 ttance, i/iiitnfiti/, quality, relation, place, time, situ- 

 nti'on, / ^session, action, and suffering. From the 

 point if view of logic, these may H>e reduced to two: 

 MI I ^tance and attribute; of metaphysics, to being 

 and accident. The Cartesians had the three cate- 

 es substance, attribute, and mode; Leibnitz 

 siiliMance, quantity, quality, action or passion, and 

 relation; and Locke substance, mode, and rela- 

 tion. J. S. Mill classifies all existences or describ- 

 aMe things as follows: (1) Feelings, or states of 

 consciousness, the most comprehensive experience 

 that the human mind can attain to, since even the 

 external world is only known as conceived by our 

 minds; (2). the minds which experience those feel- 

 : (3) the bodies, or external objects, which are 

 supposed to excite all that class of reelings that we 

 denominate sensations ; (4) the successions and co- 

 nces, the likenesses and unlikenesses, between 

 f ee 1 i ngs or states of consciousness. Although those 

 relations are considered by us to subsist between 

 the 1 todies, or things, external to our minds, we are 

 driven in the last resort to consider them as really 

 sultsisting between the states of each one's own 

 individual mind. 



The categories of Kant are conceived under a 

 totally different point of view. The Root-notions of 

 tin' understanding (Stammbegriffe des Verstandes), 

 they are the specific forms of the a priori or formal 

 element in rational cognition forms inherent in the 

 understanding, under which the mind embraces the 

 objects of actual experience. The Kantian philo- 

 sophy supposes that human knowledge is partly 

 made up of the sensations of outward . things 

 colour, sound, touch and partly of mental ele- 

 ments or functions exi *ting prior to all experience of 

 the actual world. (This is the point of difference 

 between the school of Locke, who rejected all innate 

 ideas, conceptions, or fonns, and the school of Kant. 

 No such question was raised under the Aristotelian 

 categories.) Kant's categories are as follows: (1) 

 (Quantity, including unity, multitude, totality; (2) 

 Quality, including reality, negation, limitation ; 

 (3) Relation, including substance and accident, 

 cause and effect, action and reaction; (4) Modality, 

 which includes possibility, existence, necessity. 

 These indicate the elements of our knowledge a 

 priori; and though they are the necessary con- 

 ditions under which alone experiences can be real- 

 ised to the mind, are merely subjective forms of its 

 own activity, distinct from and inapplicable to the 

 world of noumena the thing in itself that lies out- 

 side and beyond. Fichte based the whole system of 

 the categories of reality on the affirmation of itself 

 by the Ego the primitive function of self-conscious- 

 ness. Hegel carried this further, and showed that 

 t his primitive function supplied the principle needed 

 to harmonise and unify the objective and subjective 

 elements in thought. Thought and being are ulti- 

 mately identical, and the categories are thus merely 

 definite aspects or determinations ( Best! mm .uiigen ) 

 of the universal of thought, which is identical with 

 reality or actual existence. 



Ca'tenarv. The catenary is the curve formed 

 by a llexible Homogeneous cord hanging freely be- 

 tween two points of support, and acted on by no 

 other force tnan gravity, the name being suggested 

 by Lat. catena, 'a chain.' The catenary possesses 

 several remarkable properties, one of which is, that 

 its centre of Gravity (q.v.) is lower than that of any 

 curve of equal perimeter, and with the same fixed 

 points for its extremities. It is of importance for 

 the theory of suspension bridges. See BRIDGE. 



Catmi'poru, a genus of fossil tabulate coral* 

 peculiar to I'aheo/oic strata, confined in Hrituin to 

 the Silurian measures. See CORAL. 



Caleran (Gaelic, ceatharnach, 'a soldier'), 

 originally an Irish or Highland soldier, a kern; 

 usually, however, a Highland reiver or freebooter. 

 See CLAN, BLACKMAIL, ROB ROY. 



Caterpillar, the larval stage of butterflies and 

 moths { Lepidoptera ), and the representative in this 

 special order of the grub, maggot, or larva phase in 

 the life-history of many insects. 



General Structure. The caterpillar, so familiar 

 in its external appearance, has usually 12 body- 

 rings, not including the head, is provided with 

 strong biting jaws, strikingly contrasted with the 

 mouth organs of the adult, has three pairs of five- 

 jointed clawed legs on the region corresponding to 

 the thorax, and usually five rudimentary stumps or 

 pro-legs on the abdomen. These unjointed append- 

 ages are borne on the sixth to the ninth, and on the 

 twelfth segments of the body ; some of them may be 

 absent ; in the majority of cases they are adapted 

 for clambering. The body may be naked or covered 

 with hairs, bristles, and spines, which, in caterpillars 



Fig. 1. 



a, Chocrocampa Ursa, showing eye-like spots; 6, young cater- 

 pillar of Deilephila Euphorbide (after Weismann ). Cf. fig. 6. 



living an exposed life, are usually brightly coloured. 

 The large head is divided by a median line, and 

 bears six eye-spots on each side, a pair of short three- 

 jointed feelers, strong upper jaws or mandibles, 

 besides jointed palps on tne two successive pairs of 

 mouth appendages. Two well-developed spinning 

 organs open on the second pair of maxillae forming 

 the lower lip or labium. On each side, on the first 

 ring, and on the fourth to the eleventh, there are 

 nine pairs of stigmata or openings into the respira- 

 tory air-tubes. Hatschek lias observed the appear- 

 ance of three pairs of stigmata on the jaw-segments 

 of the head. The colours are familiarly bright in 

 many instances, and may have their seat in the 

 cuticle or in the skin below, or very frequently in 

 deeper regions of the body. A metallic sheen is 

 sometimes superadded. The surface is often beau- 

 tifully marked longitudinally, or transversely, or 

 with ring-spots and eye-spots. Odoriferous and 

 other glands frequently occur on the skin, and 

 are in some cases (Dicranura, Orgyia) eversible. 

 The internal anatomy of the caterpillar, though 

 essentially resembling that of the adult, differs in 

 some striking features. Thus while the larva has 

 11 to 12 separate nerve ganglia in the ventral 

 chain, the adult insect has usually only two 

 separate ganglia in the thorax, and five in the 

 abdomen. The digestive system is comparatively 

 short and simple ; the circulatory and respiratory 

 systems much like those of the adult ; a few aquatic 

 caterpillars have gill-like appendages. 



History. The caterpillar develops like any 

 other larva from the segmented egg and differen- 

 tiating embryo ; its life is usually more or less 

 active and voracious; it undergoes several moult- 



