The combination of such characters, some, as the sacral ones, altogether peculiar among Reptiles, others borrowed, as it were, from groups now distinct from each other, and all manifested by creatures far surpassing in size the largest of existing reptiles, will, it is presumed, be deemed sufficient ground for establishing a distinct tribe or sub-order of Saurian Reptiles, for which I would propose the name of Dinosauria.

Every step in the progress of this study has tended to obliterate the technical barriers by which logicians have sought to separate the inquiries relating to the several parts of man's nature.

The laws of Coexistence;-the adaptation of structure to function; and to a certain extent the elucidation of natural affinities may be legitimately founded upon the examination of fully developed species;-But to obtain an insight into the laws of development,-the signification or bedeutung, of the parts of an animal body demands a patient examination of the successive stages of their development, in every group of Animals.

Cuvier had preceded Lamarck in specifying the kinds and degrees of variation, which his own observations and critical judgment of the reports of others led him to admit.

Homologue. The same organ in different animals under every variety of form and function.

That the variability of an organism to a certain extent is a constant and certain condition of life we admit, otherwise there would be no distinguishable individuals of a species.

The combination of such characters, some, as the sacral ones, altogether peculiar among Reptiles, others borrowed, as it were, from groups now distinct from each other, and all manifested by creatures far surpassing in size the largest of existing reptiles, will, it is presumed, be deemed sufficient ground for establishing a distinct tribe or sub-order of Saurian Reptiles, for which I would propose the name of Dinosauria.