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Show 28 INTRODUCTION. . t to escape from pain. lity that is, to some few shght movcmen s . . Be:ween these two extremes, the degl'ees are mfim.te. tl In a great number of animals, however, there extsts ~10 l:r kind of intelligence, called instinct. This induces t em_ o h ation of the spectes, certain actions necessary to t e preserv ts f th but very often altogether foreign t~ the apparen~ .:~n if oattri~ individual· often also very complicated, and w 11 ' buted to in' telligence, would suppose a f.o res.i ght and k.n ow-ledge in the species that perform them m~mtely superiOr to what can possibly be grantel!. These actions, the result of instinct are not the effect of imitation, for very frequently the individ~als who execute them have never seen th.em pe.rforn~ed by others : they are not proportione~ to ordma_r~ Intelhgence, but become more singular, more wise, more dismterested, in proportion as the animals belong to less elevated class?s, and in all the rest of their actions arc more d~tll and stupi.d. They are so entirely the property of the spe?1es, that all. Jts individuals perform them in the same way Without ever Im· proving them a particle. The working bees, for instance, have always const~ucted very ingenious edifices, agreeably to the r~les of the l~1ghest geometry, and destined to lodge and nourish a }JOsterity not even their own. The solitary bee, and the wasp also, form highly complicated nests, in which to deposit tl~eir eggs. From this egg comes a worm, which has never seen Its parent, which is ignorant of the structure of the prison in which it is confined, bnt which, once metamorphosed, constructs another precisely similar. The only method of obtaining a clear idea of instinct, is by admitting the existence of innate and perpetual images or sensations in the sensorium which cause the animal to act in the same way as ordinary or accidental sensations usually do. It is a kind of perpetual vision or dream that always pursues it, and it may be considered, in all that has relation to its instinct, as a kind of somnambulism. Instinct has been granted to animals as a supplement to intelligence, to concur with it, and with strength and fecundity, in the preservation, to a proper degree, of each species. INTRODUCTION. 29 There is no visible mark of instinct in the conformation of the animal, but, as well as it can be ascertained, the inte11igence is always in proportion to the relative size of the brain and particularly of its hemispheres. ' Of Method, as applied to the .llnimal Kingdom. From what has been stated with respect to methods in general, we have now to ascertain what are the essential characters in animals, on which their primary divisions arc to be founded. It is evident they should be those which are drawn from the animal functions, that is from the sensations, and motions; for both these not only make the being an animal, but in a manner establish its degree of animality. Observation confirms this position by showing that their degrees of development and complication accord with those of the organs of the vegetative functions . The heart and the organs of the circulation form a kind of centre for the vegetative functions, as the brain and the tr1,1nk of the nervous system do for the animal ones. Now we see these two systems become imperfect and disappear together. In the lowest class of animals, where the nerves cease . to be v~sibl~, the fibres are no longer distinct, and the organs of digestiOn are simple excavations in the honogeneous mass of the body. In insects the vascular system even disappears before the nervous one; but, in general, the dispersion of the m~duiiary masses accompanies that of the muscular agents: a spmal ma:row, on which the knots or ganglions represent so ~any brams, corresponds to a body divided into numerous rmgs, supported by pairs of limbs longitudinally distributed &c. ' This correspondence of general forms, which results from · the arrangement of the organs of motion, the distribution of the nervous masses, and ~he energy of the circulating system, s~ould then be the basis of the primary divisions of the animal k~n?~om. W c will afterwards ascertain, in each of these UIVISions, what characters should succeed immediately to those and form the basis of the primary subdivisions. ' |
