by what we are pleased to call instinct, as opposed to reason. Yet there is every gradation between the two.
Among the various races of dogs, the companions of man for unnumbered centuries, we observe not only reasoning powers of a rather high order, but also distinct traces of moral sentiments, similar to those possessed by our own race. I will give no examples, for many may be found in books with which you are familiar. Actions evincing the same mental attributes are also noticed in wild animals which have been tamed. You will reply that these qualities have been developed by human education; but not so: there must have been a latent capacity in the brain to receive the education, and to manifest the results by the modification of the habits. Now, it is because we are vertebrates, and the animals of which I have spoken are vertebrates, that we understand, though imperfectly, their mental processes, and can develop the powers that are otherwise latent. Could we comprehend them more fully we would find, and we do find from time to time in the progress of our inquiries, that what was classed with instinct is really intellection.
When we attempt to observe animals belonging to another subkingdom—Articulata, for instance—such as bees, ants, termites, etc., which are built upon a totally different plan of structure, having no organ in common with ourselves, the difficulty of interpreting their intellectual processes, if they perform any, is still greater. The purposes of their actions we can only divine by their results. But any thing more exact than their knowledge of the objects within their scope, more ingenious than their methods for using those objects, more complex, yet well devised, than their social and political systems, it is impossible to conceive.
We are not warranted in assuming that these actions are instinctive, which if performed by a vertebrate we would call rational. Instead of concealing; our ignorance under a word which thus used comes to mean nothing, let us rather admit the existence here of a rational power, not only inferior to ours, but also different.
Thus proceeding, from the highest forms in each type of animal life to the lower, and even down to the lowest, we may be prepared te advance the thesis that all animals are intelligent, in proportion to the ability of their organization to manifest intelligence to us or to each other; that wherever there is voluntary motion, there is intelligence: obscure it may be, not comprehended by us, but comprehended by the companions of the same low grade of structure.
However this may be, I do not intend to discuss the subject at present, but only wish in connection with this train of thought to offer two suggestions.
The first is, that by pursuing different courses of investigation in biology, we may be led to opposite results. Commencing with the simplest forms of animal life, or with the embryo of the higher ani-
