144 
Palaeontologie. 
Eumycetes. 
von Vorschlägen von G. Andersson, Früh, Schröter, Stoller, 
Lagerheim, Nathorstu. a. Kap. 89. Die Praeparation von Diatomeen, 
Kap. 90. Gewinnung kleiner organischer Reste aus quartären Abla¬ 
gerungen. Gothan. 
Bayliss, J. S., The Biologyof Polystictus versicolor Fr. (Journ. 
of Economic Biology. Vol. III. p. 1—22. 2 plates. April 1908.) 
The author succeeded in growing this fungus from the Spore 
to the complete sporophore. In hangingdrop and also in tube cul- 
tures, the young mycelium produced from the spore soon breaks up 
into rod-like oidia such as have been described for Hypholoma 
fasciculare, and Polyporus squamosus. In flask and tube cuitures the 
oidial ^orm passed over to the mycelium form after about four 
months. Spore cuitures were also made on sterilized blocks of wood; 
the fungus was found to thrive well on Fraxinus, Aesculus, Sorbus, 
Sycamore, and Birch, whilst it grew with difficulty on blocks of 
Alder, Elm and Oak. No perfect sporophores were developed on 
the small blocs employed in the pure cuitures, nor were they pro¬ 
duced when the cuitures were transferred to larger blocks of the 
same wood as long as they were kept in the laboratorj^; when 
placed out of doors and uncovered, the cuitures quickly responded 
to the change of environment and small sporophores were developed. 
Abundance of air is probably essential for their development. 
The sporophores grow most rapidly in a warm, saturated at- 
mosphere; during cold frosty weather the growth is entirely arrested. 
The velvety zoning of the pileus is shown to be due to alternate 
checking and promoting of growth caused by varying conditions of 
atmospheric moisture; this fact was noted in the field and verified 
by laboratory experiments. The colouring of the zoning is largely 
dependant on light. The production of the dimidiate sporophore is 
attributed to the combined Stimulus of light and gravity, whilst 
pore-formation is a response to one force onl} T viz. light. Pores were 
never developed in the dark. 
Polystictus versicolor retains its vitality during long and continuous 
desiccation, a fact of importance from an economic standpoint. An 
instance is quoted where the mycelium in a block of wood was 
found to be alive and vigourous after being kept in a museum for 
4 years. 
The enz\^mes of the fungus are briefly dealt with, and an ac- 
count is given of the destruction of wood by the mycelium, and 
also of some of the Chemical changes that take place in the rotting 
wood. A. D. Cotton. 
Brooks, F.T., Observations on the Biology of Botrytis cinerea. 
(Annals of Botanv Vol. XXII. July 1908. p. 479—487.) 
The paper is the full account of the experiments summarized 
in Proc. Cambr. Soc. (v. abstract in Centralblatt Bd. 108, p. 298.) 
In dealing with the question of direct infection of the yellowing 
leaves and the non-infection of the normal green leaves, the author 
suggests the following possibilities: a) that some chemotropic sub- 
stance present in the cells of the yellowing leaf attracts the germ- 
tubes, whereas no such chemotropic influence is exerted by the 
normal leaf; b) that in the case of non infection of a normal leaf 
some substance from the epidermal cells diffuses through the cuticle 
in sufficient quantity to neutralize the effect of the small amount of 
