9i 
Cutleria multiftda ( Grev .). 
test of the health of a culture, death rapidly ensuing if the 
plants once sink and are unable to again raise themselves. 
In no case was any further advance made in the formation 
of the adult Cutleria^ thallus ; the filaments in some cases 
showed the rope-like aggregation characteristic of the main 
branches of many Ectocarpus- forms, but no fusions to a 
pseudo-tissue took place. The filamentous mass increased 
in bulk for over a month, but after that the plants began 
to be sickly, and by the end of June the whole culture was 
undoubtedly so, and portions of it commenced to die off. 
Before dying however, in July, the plants produced multi- 
locular reproductive organs in great abundance throughout 
the culture, which, on maturity, proved to be unmistakable 
antheridia of Cutleria (Fig. 3). 
In the same culture (the only one which reached this stage, 
for all the plants left at Plymouth died at an early date) 
many of the young plants had, in addition, thrown out 
Aglaozonia- lobes from their attachment discs, and some 
of these fully equalled in extent a two months’ old Aglaozonia 
grown from Cutleria- oospheres (Fig. 4). 
Although abnormal conditions may have led to patho- 
logical results, it was undoubtedly shown that Aglaozonia- 
zoospores, under certain conditions, not only give rise to 
a Protonematoid stage of Cutleria , which on impoverishment 
and exposure in a sunny window in summer became pre- 
cociously antheridial, but that they may, on the other hand, 
produce the Aglaozon ia- fo r m again, and thus the antithetic 
character of the alternation would fail to be established. 
As already indicated, these observations are still incomplete, 
since the observation of the development of the mature 
assimilating thallus of Cutleria has yet to be made ; but 
this is not absolutely essential, since a filamentous plant 
bearing oogonia, but presenting even fewer of the vegetative 
characters of a Cutleria , in that it was almost a constantly 
uniseriate filament throughout, has already been described by 
Kuckuck under the name C. multifida var. confervoides 1 . 
1 Wissenschaftliche Meeresuntersuchungen, Biolog. Anst. Helgoland, 1894, i. p. 251. 
