. Heredity and evolution in plants. Heredity; Plants. LIFE HISTORY OF A FEEN 23 16. Fertilization.—Neither the eggs nor the sperms are able, independently, to reproduce their kind. In order to accomplish this they must unite, and the fusion of the sperm and egg is fertiHzation. One of the most significant facts about fertilization in ferns is that free water is re- quired, in order that the sperms may reach the egg by their own locomotion. When the antheridia and archegonia. Fig. 23.—Fern prothallus; cross-sections showing antheridia {an), sperms {sp), and rhizoids {rh). Below at the right is
. Heredity and evolution in plants. Heredity; Plants. LIFE HISTORY OF A FEEN 23 16. Fertilization.—Neither the eggs nor the sperms are able, independently, to reproduce their kind. In order to accomplish this they must unite, and the fusion of the sperm and egg is fertiHzation. One of the most significant facts about fertilization in ferns is that free water is re- quired, in order that the sperms may reach the egg by their own locomotion. When the antheridia and archegonia. Fig. 23.—Fern prothallus; cross-sections showing antheridia {an), sperms {sp), and rhizoids {rh). Below at the right is a sperm {sp) greatly enlarged. are mature, a suitable amount of water (such as would result from a rain or a copious dew), soaking through the archegonial walls, will cause the mucilaginous matter in the neck-canal to swell. This in turn will rupture the archegonia at their distal ends, and a portion of the con- tents of the neck-canal will become extruded, while the egg will remain in the venter. The same conditions of. Please note that these images are extracted from scanned page images that may have been digitally enhanced for readability - coloration and appearance of these illustrations may not perfectly resemble the original Gager, C. Stuart (Charles Stuart), 1872-1943. Philadelphia, P. Blakiston's Son & Co.
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectplants, bookyear1920
