Chlamydospore-Formation in a Basidiomycete. 17 
CHLAMYDOSPORE-FORMATION IN THE 
BASIDIOMYCETE PLEUROTUS SUB PALM A TUS. 
By Dorothea C. E. Marryat. 
[Plate I. and Text-Fig. 1.] 
f OWARDS the end of November, 1906, fine specimens of the 
Basidiomycete Pleurotus subpalmatus Fr. were found growing 
on an old Elm tree in Caius Cricket-ground, Cambridge, where a 
large branch had been broken off by the wind. Wishing at that time 
to investigate the wood-destroying powers of various tree Fungi, I 
made pure cultures of the basidiospores, which were deposited in 
quantities on laying the hymenium face downwards on clean white 
paper. The spores were of a fine salmon-pink colour; the medium 
used for their culture was Gelatine and 10% Grape Extract. They 
germinated very readily and after about ten days a thin, greyish- 
white felt-work of mycelium was visible on the glass plates in which 
the cultures were made. 
Sterilised Elm-blocks—sections of which were previously 
examined microscopically and found to show no trace of fungi— 
were then infected with small pieces of mycelium from the plate- 
cultures. The blocks were enclosed in glass tubes plugged with 
cotton-wool and placed in a dark cupboard. 
After three weeks, small cotton-wool-like flecks of mycelium 
were visible on all the infected blocks, and a fortnight later they 
were more or less thickly covered with a fine growth of soft 
flocculent white hyphae. 
At this point, two of the blocks were fixed in absolute alcohol 
and sections cut of the wood. On examining the latter, a number 
of curious spore-like bodies were observed, both free and also 
apparently inside the wood-vessels. 
Suspicion being thus aroused, small pieces of the mycelium 
growing on the blocks were examined, and it was discovered that 
countless numbers of spores had been, and were being, produced by 
the hyphie, the fallen spores being present in such quantities that 
the latter were almost hidden by them. 
It was at first thought that some intruder must have crept into 
the cultures, but on examining more closely the hyphae which bore 
the spores, the presence of numerous “clamp-connections”— 
