[15] Radl, _loc. cit._, i., p. 50.

[16] Perrault et Duverney, _Memoires pour servir a
l'histoire des Animaux_, Paris, 1699.

[17] F. Houssay, _Nature et Sciences naturelles_, Paris,
p. 76, n.d.

[18] Foster, _loc. cit._, p. 85.

[19] Trans, by Foster, _loc. cit._, p. 113.

[20] He made a careful study of the silkworm.

[21] "Etenim, ferventi aetatis calore, Anatomica
aggressus, licet circa peculiaria fuerim solicitus, in
_perfectioribus_ tamen haec rimari sum ausus. Verum, cum
haec propriis tenebris obscura jaceant, simplicium
analogismo egent; inde _insectorum_ indago illico
arrisit; quae cum et ipsa suas habeat difficultates ad
Plantarum perquisitionem animum _postremo_ adjeci, ut
diu hoc lustrato mundo gressu retroacto Vegetantis
Naturae gradu, ad prima studia iter mihi aperirem. Sed
nec forte hoc ipsum sufficiet cum simplicior _Mineralium
Elementorumque_ mundus praeire debeat. At in immensum
excrescit opus, et meis viribus omnino impar," _Opera
Omnia_, i., p. 1, London, 1686.

[22] See particularly E. Radl, _loc. cit._. I Teil. J. V.
Carus, _Geschichte der Zoologie_, Muenchen, 1872.

[23] For a good historical account of the gradation
theories see Thienemann's paper in the _Zoologische
Annalen_(Wuerzburg) iii., pp. 185-274, 1910, from which
the quotation from Robinet is taken.

[24] _Histoire naturelle_, i., p. 13; ii, p. 9; iv., p.
101; and xiv., pp. 28-9, 1749 and later.

[25] No translation can render the beauty of the
original--"Comme tout se fait et que tout est par nuance
dans la Nature ..." (iv., p. 101).

[26] _Hist. nat._, iv., p. 5.

[27] See particularly his comparison of the skeleton of
the horse with that of man. _Hist. Nat._, iv., p. 381,
also p. 13.

[28] _Loc. cit._, p. 382.

[29] Tome xiv., pp. 311-374.

[30] Tome xiv., p. 358.

[31] See also "Oiseaux," Tome i., pp. 394, 395. Pallas in
1766 adopted for the whole animal kingdom this branching
arrangement.

[32] "But this cannot be, for it is certain by revelation
that all animals have equally participated in the grace
of creation."

[33] iv., p. 385.

[34] iv., pp. 3-110.

[35] It has been revived in our own days by Bergson,
_Matiere et Memoire_, p. 57.

[36] iv., pp. 7-15.

[37] _Anatomie Generale_, Paris, 180