. Elementary botany. Botany. Fig. 309. Mature and open archegonium of fern {Adiantuni cuneatum) witli spermatozoids making their way down tiirougti tile slime to the egg. tissue of the prothallium. The egg is in the larger part. The spermatozoids when they are swimming around over the under surfaee of tlie pro- thallium come near the neck, and here they are caught in the viscid substance which has oozed out of the canal of the arche- gonium. From here they slowdy swim down the canal, and finally one sinks into the egg, fuses with the nucleus of the latter. and the egg is then fertilized. It is
. Elementary botany. Botany. Fig. 309. Mature and open archegonium of fern {Adiantuni cuneatum) witli spermatozoids making their way down tiirougti tile slime to the egg. tissue of the prothallium. The egg is in the larger part. The spermatozoids when they are swimming around over the under surfaee of tlie pro- thallium come near the neck, and here they are caught in the viscid substance which has oozed out of the canal of the arche- gonium. From here they slowdy swim down the canal, and finally one sinks into the egg, fuses with the nucleus of the latter. and the egg is then fertilized. It is no'\- ready to grow and develop into the ten plant. This brings us back to the spor'1 phyte, which begins with the fertilized Fig. 3to. Fertilization in a fern 'Marattia). .v/, sperniato- zoid fusing with the nu- cleus of the egg. (After Campbell. I Sporophyte. 668. Embryo.—The egg first divides into iwn cells as shown in fig. 228, then into four. Mow lr(.)m each one of these (|iian(h-ants of the embryo a definite part of the plant develops, from one the lirst leaf, from one the stem, from one tlie root, and from the other the organ wliieh is called the foot, and which. 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 Atkinson, George Francis, 1854-1918. New York : H. Holt
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