of the hind and doe which constitute soine of the most valuable portions of Harvey's work. Interwoven with these observations, we find con- stant reference to the doctrines of Aristotle and of Fabricius, together with occasional quotations of the opinions of others; and when to these are added the speculations of Harvey himself, which we find scattered through every portion not only of the Exercises but also of the four additional essays with which the work concludes, we shall have enumerated the leading features of Harvey's remarkable and most interesting treatise.
Remarkable and most interesting it may well be termed, when we consider the circumstances under which its composition was attempted; for scarcely were any of the facts yet discovered upon which a consistent theory of generation might be based. Not one, indeed, of the main points. which constitute the foundation of our present views regarding the physiology of this subject, had yet been ascertained. A long interval had still to be bridged over before the first of these elementary facts was fully established. And when now, looking back upon the past, we see with what persevering industry, and by what a long
