. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. 368 THE NON-VASCULAR PLANTS properly be called spores; cells which reproduce directly are spores, and cannot properly be called gametes. Thus the fertilized egg is properly called a spore; a sex process is responsible for its origin, but it is not a sex cell itself; only gametes are sex cells. In Ulothrix we have the appearance of sex, but we do not have its differentiation; that is to say, although the sex act is performed, there appears to be no differen
. Plant life and plant uses; an elementary textbook, a foundation for the study of agriculture, domestic science or college botany. Botany. 368 THE NON-VASCULAR PLANTS properly be called spores; cells which reproduce directly are spores, and cannot properly be called gametes. Thus the fertilized egg is properly called a spore; a sex process is responsible for its origin, but it is not a sex cell itself; only gametes are sex cells. In Ulothrix we have the appearance of sex, but we do not have its differentiation; that is to say, although the sex act is performed, there appears to be no difference between the gametes, no dif- ferentiation into male and female. But in (Edogonium, another common fresh-water alga, we have distinct male and female gametes. (See Figure 165.) In this form certain cells become enlarged and rounded. The protoplast. Fig. 165. â (Edogonium. A, a young filament. B, portion of a mature filament. The largest cell is an is transformed into an egg. osmium, that is, a cell which^con- Qthej. vegetative Cells Subdi- tains an egg. The oogonium of this ° vide into smaller cells and The these produce sperms. egg. Trie oogonium i plant contains just one large egg which is richly supplied with food, indicated by the numerous light oval bodies. Near the bottom of sperms escape into the water. this picture are three antkeridia (cells They Swim actively and ap- which produce sperms). From two , , , of these antheridia sperms have es- Pear to be attracted to the caped. A third sperm, without its egg. Presently one of them cilia, may be noted at the bottom i â â¢. j r .m- of the oogonium. It has reached reacheS the eSS and fertilizes the egg and is about to fuse with it. it. The Cell which produces. 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 Coulter, John G. (John Gaylord), b. 187
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Keywords: ., bookcentury1900, bookdecade1910, booksubjectbotany, bookyear1913
