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material. Furthermore the young spider builds prac-
Concerning the origin of instincts there are several
3. Intelligent Action. You come in cold and sit down before an open fire. You push the brands together to make the fire burn. Applying once more the criterion of consciousness to this action we notice that you are conscious of the stimulus to act, of the steps of the action, and of the end to be attained, exactly as in instinctive action. But finally, and this is the essential characteristic of intelligent action, you are aware to a certain extent of the fitness of the means to the attainment of the end. This piece of knowledge you had to acquire for yourself. Erasmus Darwin a fool as a man who had never tried an exare the sources of intelligence. Intelligence is power periment. Experience and observation, not heredity, to think, and a man may be very learned-for do we Inot have learned pigs ?-and yet have very little real intelligence. Hence this is possessed by different individuals in very varying degrees.
We may now briefly compare these three kinds of
Reflex action is involuntary and unconscious. The actor may, and usually does, become conscious of the action after it has been commenced or completed, but this is not at all necessary or universal.
Instinctive action is to a certain extent voluntary and conscious. The actor is conscious of the stimulus, the means and mode, and the end or purpose of the action. Of the exact fitness or adaptation of the means to the end the actor is unconscious.
Intelligent action is conscious and voluntary. The actor is conscious of the stimulus to act, of the means and mode, and to a certain extent of the adaptation of the means to the end. This last item of knowledge, lacking in instinctive action, is acquired by experience or observation.
Reflex action may be regarded as a comparatively mechanical, though often very complex, process; the reflex ganglia appear to be hardly more than switchboards. There is stimulus of the sense-organs, and thus what Mr. Romanes has called "unfelt sensation," unfelt as far as the completion of the action is concerned. But in instinct the sensation no longer remains unfelt; perception is necessary, consciousness plays a part. And this consciousness is a vastly more subtle element, differing as much apparently from the vibration of brain, or nervous, molecules as the Geni from the rubbing of Aladdin's lamp, to borrow an illustration.
But this element of consciousness is one which it is exceedingly difficult to detect in our analysis, and yet upon it our classification and the psychic position of
an animal must to a great extent depend. The amoeba
thing for us to remember in our present ignorance is
not to be dogmatic.
Furthermore, the gain of a grain of consciousness of the adaptation of certain means to special ends changes instinctive action into intelligent, and its loss
may reverse the
that in so far as actions, even instinctive, are modified
process. Fortunately we have found
by experience, they
stincts are adapted,
or we may give to individual in
telligence the credit due really to natural selection. We must be cautious in our judgments.
These reflex actions are performed independently of consciousness or will. Consciousness may, probably does, attend the selection and grasping of food; but
most of the actions of the body will go on better without its interference. It is not yet sufficiently developed, or, so to speak, wise enough to be intrusted with much control of the animal.
Among higher worms cases of instinct seem proven. Traces of it will almost certainly be yet found much lower down. Fresh-water mussels migrate into deeper water at the approach of cold weather. And if the clam has instincts, there is no reason why the turbellaria should not also possess them. But all higher powers develop gradually, and their beginnings usually elude our search. Along the line leading from annelids to insects instinct is becoming dominant. A supraœsophageal ganglion has developed, and has been relieved of most of the direct control of the muscles. Very good sense-organs are also present. From this time on consciousness becomes clearer, and the brain is beginning to assert its right to at least know what is going on in the body, and to have something to say about it. Still, as long as the actions remain purely instinctive the brain, while conscious, is governed by heredity. The animal does as its ancestors always have. It does not occur to it to ask why it should do thus or otherwise, or whether other means would be better fitted to the end in view. It acts exactly like most of the members of our great political and theological parties. And until the animal has a better brain this is its best course and is favored by natural selection.
But the hand of even the best dead ancestors cannot always be allowed to hold the helm. The brain is still enlarging, the sense-organs bring in fuller and more definite reports of a wider environment. Greater
to modify details,
freedom of action by means of a stronger locomotive system is bringing continually and varied riences. And if, as in vertebrates, longer life be added, frequent repetition of the experience deepens the impression. Slowly, as if tentatively, the animal begins some of its instincts, at first only in slight or to adopt new lines of action not included in its old instincts, but suited to the new emergencies. This is the dawn of intelligence. Its beginnings still remain undiscovered. Mr. Darwin believes that traces of it can be found in earthworms and other annelids. He also tells us that oysters taken from a depth never uncovered by the sea, and transported inland, open their shells, lose the contained water, and die; but that left in reservoirs, where they are occasionally left uncovered for a short time, they learn to keep their shells shut, and live for a much longer time when reIf oysters can learn by expeprobably can do the same.
moved from the water. rience, lower worms
animals a little more
Certain experiments made on sea-anemones, actinæ Imand repetition under careful observation.* The obhighly organized than hydra, deserver placed on one of the tentacles of a sea-anemone paper which had been dipped in beef-juice. It was seized and carried to the mouth and here discarded. This tentacle after one or two experiments refused to have anything anything more to do with it. other tentacles could be successively cheated.
a bit of
each tentacle appear to have
been able to learn by experience, but each group in the diffuse nervous system had to learn separately.
uable results by Dr. G. H. Parker, of Harvard University. These experiments have been continued with most interesting and val