[302]. See Brock, ‘Biolog. Centralblatt,’ Bd. VIII. p. 497, 1888.
[303]. W. Richter, ‘Zur Vererbung erworbener Charaktere,’ Biolog. Centralblatt, Bd. VIII. 1888, p. 289.
[304]. This case was not observed by Darwin himself, but was communicated to him by J. P. Bishop of Perry, in North America (see ‘Kosmos,’ vol. ix. p. 458). Quite apart from the fact that it is by no means certain whether the father did not already possess an innate malformation of the thumb, exact data are wanting as to the time during which the thumb was diseased, and as to the time when the malformation of the thumb was first observed in the children and the grandchildren; whether at birth or at a later period. For a thorough criticism it would also be necessary to have figures of the thumbs. I should not have alluded to this case, because of its incomplete history, if it had not appeared to me to illustrate the ideas mentioned above. Of course I do not maintain that I have suggested the right explanation in this particular case. It is possible that the father possessed an inherent malformation of the thumb which he had forgotten by the time that he came to have children and grandchildren, and was struck by the abnormality of their thumbs.
[305]. See Burdach, ‘Lehrbuch der Physiologie,’ Bd. II, 1835-40, p. 128.
[306]. See Handwörterbuch der Physiologie von Rud. Wagner, Artikel ‘Zeugung,’ von Rud. Leuckart.
[307]. See V. Hensen, ‘Physiologie der Zeugung.’ Leipzig, 1881.
INDEX.
Abutilon, polymorphic flowers of, pp. [320], [323].
Acanthia lectularia, length of life of, [42].