Nature of Bodies_.
Highmore's book is an important one in the history of embryology, since
it is the first treatment of embryogeny from the atomistic viewpoint and
because it contains the first published observations based upon
microscopic examination of the chick blastoderm. Admittedly, the
drawings illustrating Highmore's observations upon generation are, to
use a word often applied to modern art, "interesting," but they do
derive from actual observations of developing plant and animal embryos.
His observations on the developing chick embryo are quite full,
complete, and exact, and he also records some interesting facts
regarding development of plant seeds.

Highmore's theory of development appears to have emerged directly out of
his observations of development. In this sense, his theory rests upon a
more solid base than does the developmental theory of Digby. His theory
is a mixture of vitalism and atomism, designed to eliminate the "fortune
and chance"[14] resident in Digby's concept. "Generation," he says,

...is performed by parts selected from the generators, retaining
in them the substance, forms, properties, and operations of the
parts of the generators, from whence they were extracted: and this
Quintessence or Magistery is called the seed. By which the
Individuals of every Species are multiplied...

From this, All Creatures take their beginning; some laying up the like
matter, for further procreation of the same Species.

In others, some diffus'd Atomes of this extract, shrinking themselves
into some retired parts of the Matter; become as it were lost, in a
wilderness of other confused seeds; and there sleep, till by a
discerning corruption they are set at liberty, to execute their own
functions. Hence it is, that so many swarms of living Creatures are from
the corruption of others brought forth: From our own flesh, from other
Animals, from Wood, nay, from everything putrified, these imprisoned
seminal principles are muster'd forth, and oftentimes having obtained
their freedom, by a kinde of revenge feed on their prison; and devour
that which preserv'd them from being scatter'd.[15] Accounting thus for
sexual and spontaneous generation, Highmore defines two types of seminal
atoms in the seed--"Material Atomes, animated and directed by a
spiritual form, proper to that species whose the seed is; and given to
such matter at the creation to distinguish it from other matters, and to