p. 444.

[682] 'Pom. Phys.,' p. 136.

[683] 'Ampelographie,' 1849, p. 19.

[684] Gaertner, 'Bastarderz.,' s. 606, has collected nearly all recorded
facts. Andrew Knight (in 'Transact. Hort. Soc.,' vol. ii. p. 160) goes so
far as to maintain that few varieties are absolutely permanent in character
when propagated by buds or grafts.

[685] Mr. Blyth, in 'Annals and Mag. of Nat. Hist.,' vol. xx., 1847, p.
391.

[686] 'Natural History Review,' 1862, p. 113.

[687] 'Journal of Roy. Geographical Soc.,' vol. ix., 1839, p. 275.

[688] 'Travels in Bokhara,' vol. iii. p. 151.

[689] _See_ also, on the influence of marshy pastures on the wool, Godron,
'L'Espece,' tom. ii. p. 22.

[690] Isidore Geoffroy St. Hilaire, 'Hist. Nat. Gen.,' tom. iii. p. 438.

[691] Azara has made some good remarks on this subject, 'Quadrupedes du
Paraguay,' tom. ii. p. 337. _See_ an account of a family of naked mice
produced in England, 'Proc. Zoolog. Soc.,' 1856, p. 38.

[692] 'Die Fauna der Pfahlbauten,' 1861, s. 15.

[693] 'Schweinschaedel,' 1864, s. 99.

[694] 'Travels in Siberia,' Eng. translat., vol. i. p. 228.

[695] A. R. Wallace, 'Travels on the Amazon and Rio Negro,' p. 294.

[696] 'Naturgeschichte der Stubenvoegel,' 1840, s. 262, 308.

[697] 'Hist. Nat. Gen.,' tom. iii. p. 402.

[698] 'Bull. de la Soc. Imp. d'Acclimat.,' tom. viii. p. 351.

[699] _See_ an account of Mr. Gregson's experiments on the _Abraxus
grossulariata_, 'Proc. Entomolog. Soc.,' Jan. 6th, 1862: these experiments
have been confirmed by Mr. Greening, in 'Proc. of the Northern Entomolog.
Soc.,' July 28th, 1862. For the effects of food on caterpillars, see a
curious account by M. Michely, in 'Bull. de la Soc. Imp. d'Acclimat.,' tom.
viii. p. 563. For analogous facts from Dahlbom on Hymenoptera, _see_
Westwood's 'Modern Class. of Insects,' vol. ii. p. 98. _See_ also Dr. L.
Moeller, 'Die Abhaengigkeit der Insecten,' 1867, s. 70.

[700] 'The Principles of Biology,' vol. ii. 1866. The present chapters were
written before I had read Mr. Herbert Spencer's work, so that I have not
been able to make so much use of it as I should otherwise probably have
done.

[701] 'Proc. Acad. Nat. Soc. of Philadelphia,' Jan. 28th, 1862.

[702] _See_ Mr. B. D. Walsh's excellent papers in 'Proc. Entomolog. Soc.
Philadelphia,' Dec. 1866, p. 284. With respect to the willow, _see_ idem,
1864, p. 546.

[703] _See_ his admirable Histoire des Galles, in 'Annal. des Sc. Nat.
Bot.,'