134 THE BOTANICAL MAGAZINE. [Vol. xxxtv. No. 405. 



in nature in autumn (Fig. 10, a-d). For the understanding of the 

 reader it should be added here that the shape of the sporelings differs 

 in P. tenera and P. orbiculata. Prof. Yendo considers P. tenera and 

 P. orbiculata as were different forms of P. leucosticta Thur. 2 ', to which 

 we can not agree. In P. tenera the cells are arranged in one row at 

 least to ten or as much as 37 or more, while in P. suborbiculata the 

 longitudinal arrangement of cells remains short, 10 being the maximum, 

 which soon divide longitudinally so as to take an obovate or sub- 

 orbicular outline. 



Admitting that the young forms thus raised in our culture develop 

 into well grown fronds, one may ask what becomes of the long rhizoid- 

 al filaments. It is our opinion that they become atrophied and new 

 root-like or rather hold-like fibers are emitted from cells situated in 

 the lower part of the frond, as this is suggested from the sporelings 

 having a faintly colored rhizoid, which has germinated in nature as 

 is illustrated in Fig. X2b. 



From what w r e have stated above, among other things, it seems 

 to depend upon the degree of maturity of the carpospores whether 

 they remain in a nondivided or sparingly divided state, or they soon 

 develop into young sporelings. Inmature spores have more or less 

 definable, stellate, rather thinly colored chromoplastids with small 

 vacuoles along the inner side of the wall, and the content is diffuse, 

 that is not compact, while in mature spores the chromoplastids 

 are not stellate, homogeniously colored, with no vacuole, and the 

 contents are dense and compact. 



As to the further development of carpospores remaining in the 

 latter state we know nothing at present as to whether they go to the 

 ground or grow up in a distant future to sporelings. 



At^any rate as far as we carried our studies, we did not find a 

 single cell producing male and female swarming gametes in the original 

 spore-cell and others as Prof. Yexdo has observed, which gametes 

 appear to have much a strong resemblance to Chytridean parasites. 



From this study we now believe that immature carpospores 

 appear to emit long rhizoidal filaments, while mature ones soon 

 divide, that is germinate into young fronds, either emitting short 

 rhizoids or not. In nature the immature carpospores, if they are not 

 too young, will protrude rhizoidal filaments as in our culture forms, 



1) Yexdo K. : Notes on Algae New lo Japan. IV. P. 51 (T.B.M. Vol. XXX. 

 No. 350, 1916). 



