1900] BRIEFER ARTICLES 279 
sporelings Zhurettana and Falkenbergiana and rarely some Churchiana, 
One finds all the intermediate conditions between very young Thure- 
tana in the form of a simple filament, and young Cutleria fascicled 
or with free filaments at the margin; consequently the form Zhuretiana 
gives rise to the thallus of Cutleria, and is not an abnormality of the 
cultures as Falkenberg believed. ‘The sporelings Fa/kenbergiana were 
truly thalloid, and I have shown that the column takes on a larger thallus 
than would be supposed from the cultures of the preceding authors. I 
was able to follow sufficiently far the development of the creeping 
Aglaozonia-like plate whose structure resembles that of A. melanotdea. 
This is, therefore, the first time that these plants have been found 
united, but what of their origin? They cannot be attributed to the 
zoospores of A. melanoidza, for during all the time of my observations 
these plants remained sterile. Since the parthenogenetic oospheres 
in my cultures of Cutleria gave on germination form Fadkenbergiana, 
it is to be supposed that identical plants found in nature in the same 
locality and at the same time would have the same origin. And since in 
this situation the male individuals are more numerous than the female, 
_ one may admit the antherozoids should play a part, and that fertiliza- 
tion, although not operative in my cultures, occurs in nature, and con- 
sequently that the form 7) huretiana owes its development to fertilized 
Oospheres. As for the form Churchiana, that is an anomaly, an 
example of Malkendergiana with the column changed at the tip into 
Cutleria ; it is interesting in the same manner as a flower of some 
phanerogam with metamorphosed petals and stamens. 
If the results obtained by previous authors are reconciled, we must 
acknowledge from these conclusions that alternation of generations is 
hot necessary, but rather, as one may say, facultative. Moreover, an 
oosphere of Cutleria, whether it be parthenogenetic or fertilized, may 
give on germination either Cutleria or Aglaozonia. Similarly, a z00- 
spore of Aglaozonia may produce Cutleria or Aglaozonia. But we do 
not know the conditions that govern the development from the zoo- 
Spores or oospheres in either case. 
As for the affinities of Cutleria, they are numerous. The sexual 
thallus (Cutleria proper) has a method of development that is found in 
the Sporachnacez ; it bears oogonia and antheridia similar to those of 
Sphacelariacee and Tilopteridee. The asexual thallus (Aglaozonia) 
recalls certain of the Sphacelariacez (Battersia, Sphacelaria olivacea) 
and certain of the Dictyotacee (Zonaria, Padina). 
