"Transcendental Physiology", which the editor did not approve, was
restored when the essay was re-published with others in_ 1857.]

The title Transcendental Anatomy is used to distinguish that division of
biological science which treats, not of the structures of individual
organisms considered separately, but of the general principles of
structure common to vast and varied groups of organisms,--the unity of
plan discernible throughout multitudinous species, genera, and orders,
which differ widely in appearance. And here, under the head of
Transcendental Physiology, we purpose putting together sundry laws of
development and function which hold not of particular kinds or classes
of organisms, but of all organisms: laws, some of which have not, we
believe, been hitherto enunciated.

By way of unobtrusively introducing the general reader to biological
truths of this class, let us begin by noticing one or two with which he
is familiar. Take first, the relation between the activity of an organ
and its growth. This is a universal relation. It holds, not only of a
bone, a muscle, a nerve, an organ of sense, a mental faculty; but of
every gland, every viscus, every element of the body. It is seen, not in
man only, but in each animal which affords us adequate opportunity of
tracing it. Always providing that the performance of function is not so
excessive as to produce disorder, or to exceed the repairing powers
either of the system at large or of the particular agencies by which
nutriment is brought to the organ,--always providing this, it is a law
of organized bodies that, other things equal, development varies as
function. On this law are based all maxims and methods of right
education, intellectual, moral, and physical; and when statesmen are
wise enough to see it, this law will be found to underlie all right
legislation.

Another truth co-extensive with the organic world, is that of hereditary
transmission. It is not, as commonly supposed, that hereditary
transmission is exemplified merely in re-appearance of the family
peculiarities displayed by immediate or remote progenitors. Nor does the
law of hereditary transmission comprehend only such more general facts
as that modified plants or animals become the parents of permanent
varieties; and that new kinds of potatoes, new breeds of sheep, new
races of men, have been thus originated. These are but minor
exemplifications of the law. Understood in its entirety, the