A brain is an organ which, upon the hypothesis of an independent creation of distinct species of animals, would be expected to be found in very numerous species, although they might differ widely from each other. In all the vertebrate animals this organ is the one from which, by its connection with the spinal chord, the central portion of the nervous system, that system descends through the arches of the vertebræ, and thence radiates to the various other organs of the body. The brain is the central seat of sensation, to which are transmitted, along certain nerves, the impressions produced upon or arising in the other organs; and it is the source from which voluntary activity is transmitted along other nerves to organs and muscles that are subjected to a power of movement from within. The office which such an organ performs in a complex piece of animal mechanism is therefore the same in all the vertebrate animals in which it is found; and it would necessarily be found to be constructed upon the same uniform plan, and with just the degree of uniformity and adaptation which would fit it to perform its office in the particular species of animal to which it might be given. In point of fact, we find this office of the brain performed in all the vertebrate animals upon the same uniform plan, with the necessary adaptations to the various structures of the different animals. Resemblances, therefore, in the convolutions of different parts of this organ, as found in different vertebrate animals, however close they may be, prove nothing more than the adoption of a general plan for the production of objects common to the whole class of the vertebrate animals; and unless we can find other and independent proof that one species was descended from another by connection of lives with lives through successive generations, the hypothesis of special creations of the different species is not excluded by the facts.