part appear successively, and taking the moment
of _appearance_ for the moment of _formation_ he imagined
_epigenesis_." (P. 165.)

On the contrary, says M. Flourens (p. 167),

"The new being is formed at a stroke (_tout d'un coup_), as a
whole, instantaneously; it is not formed part by part, and at
different times. It is formed at once; it is formed at the single
_individual_ moment at which the conjunction of the male and female
elements takes place."

It will be observed that M. Flourens uses language which cannot be
mistaken. For him, the labours of Von Baer, of Rathke, of Coste, and
their contemporaries and successors in Germany, France, and England, are
non-existent; and, as Darwin "_imagina_" natural selection, so Harvey
"_imagina_" that doctrine which gives him an even greater claim to the
veneration of posterity than his better known discovery of the
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 the progressive
modification of living beings. He whose mind remains uninfluenced by an
acquaintance with the phaenomena 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 primaeval 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.

FOOTNOTES:

[65] "Die Radiolarien: eine Monographie," p. 231.

[66] Space will not allow us to give Professor Koelliker's arguments in
detail; our readers will find a full and accurate version of them in the
_Reader_ for August 13th and 20th, 1864.

[67] If, on the contrary, we follow the analogy of the more complex
forms of Agamogenesis, such as that exhibited by some _Trematoda_ and by
the _Aphides_, the Hyaena must produce, asexually, a brood of asexua