. Elementary botany. Botany. SPIKOGYRA. 141 ing cells, and the supplying cell may be the smaller, this is not general. We say, therefore, that there is no diflerentiation among the gametes, so that usuallj- before tlie protoplasm begins to move one cannot say which is to be the supplying and whicli the receiving gamete. 296. Position of the plant spirogyra.—From our study then we see that there is pjractically no differentiation among the vegetative cells, except where lioldfasts grow out from some of the cells for support. They are all alike in form in capacity for growth, division, or multip
. Elementary botany. Botany. SPIKOGYRA. 141 ing cells, and the supplying cell may be the smaller, this is not general. We say, therefore, that there is no diflerentiation among the gametes, so that usuallj- before tlie protoplasm begins to move one cannot say which is to be the supplying and whicli the receiving gamete. 296. Position of the plant spirogyra.—From our study then we see that there is pjractically no differentiation among the vegetative cells, except where lioldfasts grow out from some of the cells for support. They are all alike in form in capacity for growth, division, or multiplication of the threads. Each cell is practically an independent plant. There is no differ- entiation between vegetative cell and conjugating cell. All the cells are potential gametes. Finally there is no structural differentiation between the gametes. This indicates then a simple condition of things, a low grade of organization. 297. The alga spirogyra is one of the representatives of the lower algje belonging to the group called Conjugata. Zygnema with star-shaped chloro- plasts, mougeotia with straight or sometimes twisted chlorophyll bands, be- long to the same group. In the latter genus only a portion of the protoplasm of each cell unites to form the zygospore, which is located in the tube between the Fig. 133- IVIicrasterias Fig. 134- 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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