1917] DUNN—DUMONTIA 439 



was probably present originally in the chroma tophore. The 

 presence or absence of chromatophores in these cells could have 

 been more readily determined if living plants had been available 

 for examination. However, even in the preserved material it 

 should be possible to distinguish the chromatophores from the 

 cytoplasm. The protoplasm of the chromatophores is apparently 

 homogeneous; they contain no visible vacuoles and have a definite 

 outline. Many spermatium mother cells were seen which showed 

 intermediate stages in the disappearance of the chromatophore and 

 the formation of the granular cytoplasm (rig. 19). 



Osterhout (11) states that a reduced chromatophore is present 

 in the young spermatium of Batrachospermum. This chromato- 

 phore disappears when the young spermatium matures. Wolfe 

 (19) observed the division of the chromatophore in the spermatium 

 mother cell of Nemalion in preparation for the formation of the 

 spermatium. The chromatophore is for a time visible in the young 

 spermatium and then disappears. Immediately after its disap- 

 pearance a mass of deep staining cytoplasm is seen at one end 

 of the spermatium. Wolfe believes that at least a portion of this 

 cytoplasm has been derived from the protoplasm of the chromato- 

 phore. No other workers, with the possible exception of Yama- 

 nouchi, have seen chromatophores in the spermatia or in their 

 mother cells. Yamanouchi (20) states that the sperm mother 

 cells contain fine granular cytoplasm and generally no plastids. 

 Chromatophores are present in all the genera, either in the imme- 

 diate or somewhat remote ancestors of the spermatium mother 

 cells. Svedelius (14) states that he did not actually observe the 

 disappearance of chromatophores in Martensia, but he believes 

 that the protoplasm in the chromatophores of certain cells is used 

 in forming the granular cytoplasm of their daughters which do not 

 contain any chromatophores. 



Spermatia. — No stages were seen showing a uninucleate sper- 

 matium mother cell. This cell in the earliest stages observed is 

 binucleate (rig. 16). The first spermatium is cut off obliquely 

 (figs. 15, 17, 19). The mother cell than elongates, again becomes 

 binucleate (rig. 17), and a second spermatium is cut off. Many 

 spermatia were seen in the swollen gelatinous sheath enveloping 



