90 



PLANT MORPHOLOGY 



mon along the Pacific coast. It grows in tide pools on rocks and on other 

 algae. It is a more highl}^ developed but more typical red alga than any 

 of the others that have been discussed. The plant body, reaching a 

 length of 25 cm., is filamentous and polysiphonous, being made up of an 



F G H 



Fig. 76. Batrachosperrrmm. A, antheridial branch with globular antheridia, one of which 

 has liberated its protoplast; B, young carpogonial branch, the terminal cell forming the 

 carpogonium and trichogyne; C, mature procarp with nucleated carpogonium and swollen 

 trichogyne; D, later stage, showing spermatium united with tricliogyne and male nucleus 

 fusing with carpogonial nucleus; E, completed fusion of male and female nuclei; F, develop- 

 ment of gonimoblasts from carpogonium, a sterile branch arising on the left; G, further 

 development of gonimoblasts and sterile filaments; H, formation of carpospores; A to F, 

 X960; G and H, X720. {After Kylin.) 



axial row of elongated cells surrounded and completely covered by several 

 rows of smaller peripheral cells that are cut off from the central cells by 

 longitudinal divisions. Growth occurs by means of an apical cell. 



The reproductive features of Polysiphofiia are complex. Nonmotile 



