The cell in development and inheritance . erythrophilous, as de-scribed by Auerbach in , while confirming thisobservation in some cases, finds thereaction to be inconstant, thoughthe germ-nuclei usually show markeddifferences in their staining-capac-ity. These are ascribed by Stras-burger (92, 94) to differences inthe conditions of nutrition; byZacharias and Schwarz to corre-sponding differences in chemicalcomposition, the male nucleus beingin general richer in nuclein, and thefemale nucleus poorer. This dis-tinction disappears during fertiliza-tion, and Strasburger has obse
The cell in development and inheritance . erythrophilous, as de-scribed by Auerbach in , while confirming thisobservation in some cases, finds thereaction to be inconstant, thoughthe germ-nuclei usually show markeddifferences in their staining-capac-ity. These are ascribed by Stras-burger (92, 94) to differences inthe conditions of nutrition; byZacharias and Schwarz to corre-sponding differences in chemicalcomposition, the male nucleus beingin general richer in nuclein, and thefemale nucleus poorer. This dis-tinction disappears during fertiliza-tion, and Strasburger has observed, in the case of gymnosperms (after treatment with amixture of fuchsin-iodine-green), that the paternal nucleus, which is at first cyanophil-ous, becomes erythrophilous, hke the egg-nucleus before the pollen-tube has reachedthe egg. Within the egg both stain exactly alike. These facts indicate, as Strasburgerinsists, that the differences between the germ-nuclei of plants are, as in animals, of atemporary and non-essential Fig. 108. — Fertilization in a cycad, Zamia. [Webber.] A. Spermatozoid. B. The same after entrance into the egg, showing nucleus («) and cilia-bearing band {c). C. The ovum shortly after entrance of the spermatozoid. D. Union of the germ-nuclei, cilia-bearing band nearperiphery {c). FERTILIZATION IN PLANTS 221 The nature and origin of the achromatic elements involved in thefertilization of plants is still almost wholly in the dark. No observerhas yet succeeded in observing either centrosomes or asters in thefertilization of the thallophytes, despite the fact that in some of theseforms mitosis takes place with both these structures in a mannernearly analogous to that observed in animals.^ In the cycads Zamiaand Cycas, Webber and Ikeno (98) agree that the entire spermato-zoid enters, but only the nucleus appears to be concerned in fertiliza-tion. The cilia-bearing band — a product of the blepharoplast, and,as described at page 175, probably
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