Note 113 — IV. THE CONTINUITY OF THE GERM-PLASM AS THE FOUNDATION OF A THEORY OF HEREDITY.

[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.]