Читать книгу The Foundations of the Origin of Species - Чарльз Дарвин, Darwin Charles - Страница 4

The mental powers of different animals in wild and tame state [present still greater difficulties] require a separate section. Be it remembered I have nothing to do with origin of memory, attention, and the different faculties of the mind88, but merely with their differences in each of the great divisions of nature. Disposition, courage, pertinacity «?», suspicion, restlessness, ill-temper, sagacity and «the» reverse unquestionably vary in animals and are inherited (Cuba wildness dogs, rabbits, fear against particular object as man Galapagos89). Habits purely corporeal, breeding season &c., time of going to rest &c., vary and are hereditary, like the analogous habits of plants which vary and are inherited. Habits of body, as manner of movement do. and do. Habits, as pointing and setting on certain occasions do. Taste for hunting certain objects and manner of doing so, – sheep-dog. These are shown clearly by crossing and their analogy with true instinct thus shown, – retriever. Do not know objects for which they do it. Lord Brougham’s definition90. Origin partly habit, but the amount necessarily unknown, partly selection. Young pointers pointing stones and sheep – tumbling pigeons – sheep91 going back to place where born. Instinct aided by reason, as in the taylor-bird92. Taught by parents, cows choosing food, birds singing. Instincts vary in wild state (birds get wilder) often lost93; more perfect, – nest without roof. These facts [only clear way] show how incomprehensibly brain has power of transmitting intellectual operations.

Faculties94 distinct from true instincts, – finding [way]. It must I think be admitted that habits whether congenital or acquired by practice [sometimes] often become inherited95; instincts, influence, equally with structure, the preservation of animals; therefore selection must, with changing conditions tend to modify the inherited habits of animals. If this be admitted it will be found possible that many of the strangest instincts may be thus acquired. I may observe, without attempting definition, that an inherited habit or trick (trick because may be born) fulfils closely what we mean by instinct. A habit is often performed unconsciously, the strangest habits become associated, do. tricks, going in certain spots &c. &c., even against will, is excited by external agencies, and looks not to the end, – a person playing a pianoforte. If such a habit were transmitted it would make a marvellous instinct. Let us consider some of the most difficult cases of instincts, whether they could be possibly acquired. I do not say probably, for that belongs to our 3rd Part96, I beg this may be remembered, nor do I mean to attempt to show exact method. I want only to show that whole theory ought not at once to be rejected on this score.

Every instinct must, by my theory, have been acquired gradually by slight changes «illegible» of former instinct, each change being useful to its then species. Shamming death struck me at first as remarkable objection. I found none really sham death97, and that there is gradation; now no one doubts that those insects which do it either more or less, do it for some good, if then any species was led to do it more, and then «?» escaped &c. &c.

Take migratory instincts, faculty distinct from instinct, animals have notion of time, – like savages. Ordinary finding way by memory, but how does savage find way across country, – as incomprehensible to us, as animal to them, – geological changes, – fishes in river, – case of sheep in Spain98. Architectural instincts, – a manufacturer’s employee in making single articles extraordinary skill, – often said seem to make it almost «illegible», child born with such a notion of playing99, – we can fancy tailoring acquired in same perfection, – mixture of reason, – water-ouzel, – taylor-bird, – gradation of simple nest to most complicated.

Bees again, distinction of faculty, – how they make a hexagon, – Waterhouse’s theory100, – the impulse to use whatever faculty they possess, – the taylor-bird has the faculty of sewing with beak, instinct impels him to do it.

Last case of parent feeding young with different food (take case of Galapagos birds, gradation from Hawfinch to Sylvia) selection and habit might lead old birds to vary taste «?» and form, leaving their instinct of feeding their young with same food101, – or I see no difficulty in parents being forced or induced to vary the food brought, and selection adapting the young ones to it, and thus by degree any amount of diversity might be arrived at. Although we can never hope to see the course revealed by which different instincts have been acquired, for we have only present animals (not well known) to judge of the course of gradation, yet once grant the principle of habits, whether congenital or acquired by experience, being inherited and I can see no limit to the [amount of variation] extraordinariness «?» of the habits thus acquired.

Summing up this Division. If variation be admitted to occur occasionally in some wild animals, and how can we doubt it, when we see [all] thousands «of» organisms, for whatever use taken by man, do vary. If we admit such variations tend to be hereditary, and how can we doubt it when we «remember» resemblances of features and character, – disease and monstrosities inherited and endless races produced (1200 cabbages). If we admit selection is steadily at work, and who will doubt it, when he considers amount of food on an average fixed and reproductive powers act in geometrical ratio. If we admit that external conditions vary, as all geology proclaims, they have done and are now doing, – then, if no law of nature be opposed, there must occasionally be formed races, [slightly] differing from the parent races. So then any such law102, none is known, but in all works it is assumed, in «?» flat contradiction to all known facts, that the amount of possible variation is soon acquired. Are not all the most varied species, the oldest domesticated: who «would» think that horses or corn could be produced? Take dahlia and potato, who will pretend in 5000 years103 «that great changes might not be effected»: perfectly adapted to conditions and then again brought into varying conditions. Think what has been done in few last years, look at pigeons, and cattle. With the amount of food man can produce he may have arrived at limit of fatness or size, or thickness of wool «?», but these are the most trivial points, but even in these I conclude it is impossible to say we know the limit of variation. And therefore with the [adapting] selecting power of nature, infinitely wise compared to those of man, «I conclude» that it is impossible to say we know the limit of races, which would be true «to their» kind; if of different constitutions would probably be infertile one with another, and which might be adapted in the most singular and admirable manner, according to their wants, to external nature and to other surrounding organisms, – such races would be species. But is there any evidence «that» species «have» been thus produced, this is a question wholly independent of all previous points, and which on examination of the kingdom of nature «we» ought to answer one way or another.