rience. Evidently, therefore, great wisdom may be attained even with small intelligence, if only the experience be proportionally great. Wisdom increases with experience without limit, if only the plasticity of the brain, or its capacity to receive and retain impressions, remain unimpaired. Now, suppose a number of the ancestors of the bees many hundred thousand years ago, before these specific instincts were developed; suppose, further, that these individual insects had continued to live from that time to this, and retained their brain-plasticity unimpaired. Even with the smallest modicum of intelligence, such instincts would, by experience, slowly improve their habits from year to year, from century to century, from millennium to millennium, until they would reach a surprising skill in accomplishing the most complex results. This would be habit, not instinct. The habit so long forming, so useful, and therefore so invariable, would of course be embodied in a very decided brain-structure. Now, precisely the same result is far more perfectly reached by the experience of many generations transmitted and accumulated by the law of inheritance. I say more perfectly, because of the natural selection of only the fittest in each generation.
Thus we see that instinctive wisdom is also the result of experience, but it is ancestral, and not individual experience. Individual experience is first fixed in habit, and then habit is transmitted and petrified in instinct. In a note published in the Philosophical Magazine, April, 1871, I speak of instinct as "inherited experience." I did not then know that I had been anticipated by a few months by Hering ("Archives des Science," February, 1871), who calls instinct "inherited memory." These are but different modes of expressing the same idea. Intelligence works by individual experience treasured in memory; instinct by racial or communal experience treasured in inherited structure. But memory is evidently the result of brain-structure formed by experience; therefore also is instinct inherited memory. Again, knowledge is remembered experience; therefore is instinct also inherited knowledge. Thus experience, memory, knowledge, things which seem to us so indissolubly connected with individual identity, are also sometimes inherited.
Thus, then, the sum of experience and the mental wealth which is accumulated by experience consists of two parts, individual and inherited. In man the individual acquisition is large, and the inheritance is comparatively small. In the lower animals the individual acquisition is small, while the inheritance is large. In bees the wealth is almost wholly inheritance.
We now easily see why intelligence varies inversely as instinct—why high intelligence seems incompatible with remarkable and invariable instinct. It is because, with high intelligence, actions are so varied, in different individuals and in different generations, that it is impossible that their results should accumulate and become petrified in structure. But, in the lower animals, the conditions of life are nar-
