. Botany of the living plant. Botany. Fic. 335- Gametes of vai^ious Siphonales, and Siphouocladiales, illustrating diilerentiation of male and female. i=Acctabidana, isogametes ; W^Bryopfiis ; iu = Codium( ; \\' â Sphae}OpUa ; v^Vaucheria. In iv. and v. the large egg is stationary, while the smaller spermatozoid is motile. (Taken from Oltmanns' Algiu:.) Spliaeroplea, where the large egg is non-motile (iv.), a condition still more accentuated in Vaucheria (v.), which is the most advanced of all in sexual differentiation. The sex-organs of Vaucheria arise close together as short lateral branches
. Botany of the living plant. Botany. Fic. 335- Gametes of vai^ious Siphonales, and Siphouocladiales, illustrating diilerentiation of male and female. i=Acctabidana, isogametes ; W^Bryopfiis ; iu = Codium( ; \\' â Sphae}OpUa ; v^Vaucheria. In iv. and v. the large egg is stationary, while the smaller spermatozoid is motile. (Taken from Oltmanns' Algiu:.) Spliaeroplea, where the large egg is non-motile (iv.), a condition still more accentuated in Vaucheria (v.), which is the most advanced of all in sexual differentiation. The sex-organs of Vaucheria arise close together as short lateral branches {V. sessilis), or borne together on the same branch [V. terreslris, Fig. 336). The antheridia are horn-like, curved bodies, the oogonia are oval. In the antheridium a septum cuts off the multi-nucleate protoplast from the parent tube : each nucleus becomes the centre of a spindle-shaped sperma- tozoid ; and these escape, with their paired cilia pointing fore and aft, through an opening at the distal end. The oogonium also at first contains numerous nuclei embedded in proto- nlasm stored with many globules of oil. r - ° Fig. 336. But, as theOVUm matures, all the nuclei Sexual branch of vaucheria lernslns. , , , â , . bearing distallv a cur\'ed antheriditim, and but one wander back into the parent right and left oval 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 Bower, F. O. (Frederick Orpen), 1855-1948. London, Macmillan and co. , limited
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1919
