37 
Marine Fungi Imperfecti. 
part in the disintegration of seashore organisms. Cultures bearing 
on their life histories and roles were commenced in the laboratory, 
and the description of new species was held over pending the result 
of these and of wider observations on their occurrence. As these, 
not yet complete, must he interrupted for a time, it has been 
decided to issue a preliminary description of some of the new forms. 
Since an examination of the named material at Kew, of 
numerous specimens from various points along the coast, and of 
laboratory cultures has led me to the conclusion that the form, 
described in 1888 as Cladosporium algarum, and later as Hetero- 
sporiiwi, should be replaced in the former genus, a review of new 
evidence and a resume of its position seem necessary, especially as 
this is one of the most abundant and widely distributed forms and 
consequently the more likely to find its way into collections. In its 
occurrence and habits it appears to be as cosmopolitan as the 
ubiquitous Cladosporium herbarum, abounding wherever rotting or 
dried fronds of Laminaria strew the upper beach. The conidia 
germinate rapidly, and the fronds, a few days after being cast up, 
become covered with tiny olive-coloured spots, which quickly 
extend their margins and run into one another, ultimately covering 
the whole with a thick felt, varying in colour from olive-green to 
black according to the humidity of the atmosphere and the growth 
more or less dependent on it. During dry weather growth is 
restricted, and the conidia are either blown away or fall into the 
thicket of conidiophores, which become darker in colour and cause 
the infected areas to stand out clearly against the usually bleached 
fronds. The conidiophores, at this stage, present the sharply 
truncated appearance of Fig. 1, 7. They possess, however, the 
power of renewing their growth on the recurrence of moist 
conditions, and produce either new conidia or pale coloured elonga¬ 
tions of themselves as in Fig. 1, 5. The rapid and varied changes 
in atmospheric conditions preventanygreatdevelopment of the latter, 
except during a continuation of moist weather, when the fronds 
become coated with a furry out-growth laden with dusty masses of 
olive conidia. Portions of infected thalli placed in moist stoppered 
vessels produce this growth in a few days. 
That the fungus is not restricted to the region above high tide, 
is evident from the fact that fresh Laminaria fronds, collected from 
the tidal area, on isolation in the laboratory usually develop a 
luxuriant growth of Cladosporium. The conidia also germinate 
freely in salt water. 
