. Practical botany. Botany. 202 PRACTICAL BOTANY 186. Increase in complexity of sex organs and gametes. It is to be especially noted that in other algae which we have studied reproduc- tive bodies were formed from cells which at the out- set were vegeta- tive cells. In Vau- cheria sex organs are made primarily for the work of reproduction, an interestmg divi- sion of labor in the plant. In some green algae, as GEdogonium (Figs. 1H4 and 165), vegetative cells are thus formed into oogonia and antheridia. It is also im- portant to note that in Ph'uro- coccus the entire plant might divide ^'egetat
. Practical botany. Botany. 202 PRACTICAL BOTANY 186. Increase in complexity of sex organs and gametes. It is to be especially noted that in other algae which we have studied reproduc- tive bodies were formed from cells which at the out- set were vegeta- tive cells. In Vau- cheria sex organs are made primarily for the work of reproduction, an interestmg divi- sion of labor in the plant. In some green algae, as GEdogonium (Figs. 1H4 and 165), vegetative cells are thus formed into oogonia and antheridia. It is also im- portant to note that in Ph'uro- coccus the entire plant might divide ^'egetatively into two new plants; or, in relatives of Ph'urococcus, the entu-e plant might become a spore ease (spo- rangium), producing zo()spores. In OJadophora, zoospores are formed, together witli zoospore-like gametes, the latter uniting. Fig. 165. Reproduction in CEdogonium nodosum A, holdfast cell and two vegetative Cells; B, part of a plant in whicli are an oogonium (o), containing egg, and two groups of antheridia (a), which have not yet formed sperms; C, part of a plant in whicli is an oogo- nium (o), which, by breaking away of one vegetative cell, has made a place for the sperm to enter, so that a fertilized egg or oospore has been formed, as is shown by its heavy inner wall; D, a zoospore of Qidogoniuiii, —D redrawn from Pringsheim. All greatly enlarged. 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 Bergen, Joseph Y. (Joseph Young), 1851-1917; Caldwell, Otis William, 1869- joint author. Boston, New York [etc. ] Ginn and company
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