The Reproduction of Ahnfeltia plicata. 5 
equal size, but these cells are not the spores. These were 
first described in 1893 by BurrHam and Scumirz, who found 
that the nemathecial filaments produce at the end each a 
sporangium which. gives rise to one monospore. 
BurFHAM observed the escaping monospores which were 
ellipsoid, about 15 x long, and 7 « thick, thus much larger 
than the cells of the nemathecial filaments. He gives good 
figures of these organs (1893, figs. 43, 44). As cited by 
BUFFHAM from a letter from BORNET, this prominent French 
algologist had observed such spores as early as 1857. 
SCHMITZ's observations on the spores agreed with those of 
BurFHAM, but he also studied the structure of the nema- 
thecia of this and the related species A. sefacea, and arrived 
at the conclusion that the nemathecia were not organs of 
the Ahnfeltia but that they belonged to a parasite, which 
he called Sterrocolax decipiens, growing on the surface of 
Ahnfeltia and penetrating into the cortex of the latter with 
numerous “Senker”. The author admits, however, that the 
phenomena here described, which he had observed most 
distinctly in A. selacea, were not easy to observe in A. plicata. 
SCHMITZ's inference as to the parasitical character of the 
nemathecia was only founded on the presence of the 
said processes penetrating into the cortex, and not on 
the study of the development of the nemathecia. His in- 
ference is, therefore, not conclusive, for the processes 
might also be explained as secondary formations developed 
from the base of the nemathecium produced by the Ahn- 
feltia. If the nemathecia were not organs of Ahnfellia, it 
must be concluded that no kind of reproductive organs 
had ever been observed in these Algæ. Scumirz indeed draws 
this conclusion for the whole genus Ahnfeltia (1894, p. 397, 
1896, p. 366), but this is a priori highly improbable, in 
