circulation of the blood.

Language such as that we have quoted is, in fact, so preposterous, so
utterly incompatible with anything but absolute ignorance of some of
the best established facts, that we should have passed it over in
silence had it not appeared to afford some clue to M. Flourens'
unhesitating, 'a priori', repudiation of all forms of the doctrine of
progressive modification of living beings. He whose mind remains
uninfluenced by an acquaintance with the phenomena of development, must
indeed lack one of the chief motives towards the endeavour to trace a
genetic relation between the different existing forms of life. Those
who are ignorant of Geology, find no difficulty in believing that the
world was made as it is; and the shepherd, untutored in history, sees
no reason to regard the green mounds which indicate the site of a Roman
camp, as aught but part and parcel of the primeval hill-side. So M.
Flourens, who believes that embryos are formed "tout d'un coup,"
naturally finds no difficulty in conceiving that species came into
existence in the same way.