to the thoughts which the study of nature may call forth,
any more than there is a limit to the number of the rays of the
sun.

This blade of grass grows as high as it can, the nightingale there
sings as sweetly as it can, the goldfinches feed to their full
desire and lay down no arbitrary rules of life; the great sun above
pours out its heat and light in a flood unrestrained. What is the
meaning of this hieroglyph, which is repeated in a thousand thousand
other ways and shapes, which meets us at every turn? It is evident
that all living creatures, from the zoophyte upwards, plant,
reptile, bird, animal, and in his natural state--in his physical
frame--man also, strive with all their powers to obtain as perfect
an existence as possible. It is the one great law of their being,
followed from birth to death. All the efforts of the plant are put
forth to obtain more light, more air, more moisture--in a word, more
food--upon which to grow, expand, and become more beautiful and
perfect. The aim may be unconscious, but the result is evident. It
is equally so with the animal; its lowest appetites subserve the one
grand object of its advance. Whether it be eating, drinking,
sleeping, procreating, all tends to one end, a fuller development of
the individual, a higher condition of the species; still further, to
the production of new races capable of additional progress. Part and
parcel as we are of the great community of living beings,
indissolubly connected with them from the lowest to the highest by a
thousand ties, it is impossible for us to escape from the operation
of this law; or if, by the exertion of the will, and the resources
of the intellect, it is partially suspended, then the individual may
perhaps pass away unharmed, but the race must suffer. It is, rather,
the province of that inestimable gift, the mind, to aid nature, to
smooth away the difficulties, to assist both the physical and mental
man to increase his powers and widen his influence. Such efforts
have been made from time to time, but unfortunately upon purely
empirical principles, by arbitrary interference, without a long
previous study of the delicate organization it was proposed to
amend. If there is one thing our latter-day students have
demonstrated beyond all reach of cavil, it is that both the physical
and the mental man are, as it were, a mass of inherited
structures--are built up of partially absorbed rudimentary organs
and primitive conceptions, m