[23]. Bronn, ‘Klassen und Ordnungen des Thierreichs,’ Bd. III. p. 466; Leipzig.
[24]. Bronn, l. c.
[25]. Cf. the article ‘Mort’ in the ‘Encyclop. Scienc. Méd.’ vol. M. p. 520.
[26]. Roux, in his work ‘Der Kampf der Theile im Organismus,’ Jena 1881, has attempted to explain the manner in which division of labour has arisen among the cells of the higher organisms, and to render intelligible the mechanical processes by which the purposeful adaptations of the organism have arisen.
[27]. von Berlepsch, ‘Die Biene und ihre Zucht,’ etc.
[28]. Oken, ‘Isis,’ 1844, p. 506.
[29]. von Berlepsch, l. c., p. 165.
[30]. Cf. August Gruber, ‘Der Theilungsvorgang bei Euglypha alveolata,’ and ‘Die Theilung der monothalamen Rhizopoden,’ Z. f. W. Z., Bd. XXXV. and XXXVI., p. 104, 1881.
[31]. Cf. Victor Hensen, ‘Physiologie d. Zeugung,’ p. 152.
[32]. Cf. J. Carrière, ‘Ueber Regeneration bei Landpulmonaten,’ Tagebl. der 52. Versammlg. deutsch. Naturf. pp. 225-226.