. Elements of plant biology. Plant physiology. 200 ORIGIN OF SEX AND OF THE SOMA cate threads of cytoplasm (Figs. 27, 28, A-C). V. globator, which is larger and less variable in size, has its cells much closer together and joined to one another by stout angular projections from the cytoplasm of the cell bodies (Fig. 29). It is interesting to note that V. aureus has larger green male gametes (Fig. 28, E), yvhile V. globator has smaller very thin sperms, with the hinder end yellow and the two flagella usually attached about the middle of the body (Fig. 28, F), thus departing much further than th
. Elements of plant biology. Plant physiology. 200 ORIGIN OF SEX AND OF THE SOMA cate threads of cytoplasm (Figs. 27, 28, A-C). V. globator, which is larger and less variable in size, has its cells much closer together and joined to one another by stout angular projections from the cytoplasm of the cell bodies (Fig. 29). It is interesting to note that V. aureus has larger green male gametes (Fig. 28, E), yvhile V. globator has smaller very thin sperms, with the hinder end yellow and the two flagella usually attached about the middle of the body (Fig. 28, F), thus departing much further than the sperms of V. aureus from the structure of the primitive Chlamydomonadine cell, though still showing clear traces of derivation from that structure. The sperms of V. globator are nearly. Fig. 29.—Vegetative cells of V. globator seen in profile of surface of coenobium. Note cell walls and broad protoplasmic connexions. The cell on the left is a young parthenogonidium. x i,6oo. as much reduced and highly specialised as those of green plants very much higher in the scale of vege- tative structure. The extreme contrast between the male and female gametes in size, shape and structure is very obvious (Fig. 28, G), though each may be clearly derived from the Chlamydomonadine cell through the stages of differentiation we have traced. Nature and Significance of the DifEerentiation between Male and Female Gametes.—The wide difference in structure and function between the male and female gametes of Volvox globator is repeated in the sexual differentiation of gametes in the vast majority of organisms, including, all the higher forms of hfe, both. 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 Tansley, Arthur George, 1871-. London, George Allen & Unwin Ltd. ; New York, Dodd, Mead & Co
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Keywords: ., bookcentury1900, bookdecade1920, booksubjectplantph, bookyear1922
