[108]. F. M. Balfour, ‘Comparative Embryology,’ vol. i. p. 69.
[109]. Arch. f. mikr. Anat., Bd. 23. p. 182, 1884.
[110]. Born, ‘Biologische Untersuchungen,’ I, Arch. Mikr. Anat., Bd. XXIV.
[111]. Roux, ‘Beiträge zum Entwicklungsmechanismus des Embryo,’ 1884.
[112]. O. Hertwig, ‘Welchen Einfluss übt die Schwerkraft,’ etc. Jena, 1884.
[113]. [Our present knowledge of the development of vegetable ova (including the position of the parts of the embryo) is also in favour of the view that it is not influenced by external causes, such as gravitation and light. It takes place in a manner characteristic of the genus or species, and essentially depends on other causes which are fixed by heredity, see Heinricher ‘Beeinflusst das Licht die Organanlage am Farnembryo?’ in Mittheilungen aus dem Botanischen Institute zu Graz, II. Jena, 1888.—S. S.]
[114]. E. van Beneden, ‘Recherches sur la maturation de l’œuf,’ etc., 1883.
[115]. M. Nussbaum, ‘Ueber die Veränderung der Geschlechtsprodukte bis zur Eifurchung,’ Arch. Mikr. Anat., 1884.
[116]. Eduard Strasburger, ‘Neue Untersuchungen über den Befruchtungsvorgang bei den Phanerogamen als Grundlage für eine Theorie der Zeugung.’ Jena, 1884.
[It is now generally admitted that, in the Vascular Cryptogams, as also in Mosses and Liverworts, the bodies of the spermatozoids are formed by the nuclei of the cells from which they arise. Only the cilia which they possess, and which obviously merely serve as locomotive organs, are said to arise from the surrounding cytoplasm. It is therefore in these plants also the nucleus of the male cell which effects the fertilization of the ovum. See Göbel, ‘Outlines of Classification and Special Morphology,’ translated by H. E. F. Garnsey, edited by I. B. Balfour, Oxford, 1887, p. 203, and Douglas H. Campbell, ‘Zur Entwicklungsgeschichte der Spermatozoiden,’ in Berichte d. deutschen bot. Gesellschaft, vol. v (1887), p. 120.—S. S.]