410 Proceedings of Boy al Soeiety of Edinburgh. [june 18, 
sulphate), by M. Marguerite-Delacharlonny* (a well-known French 
scientist), which entirely confirms my work. 
The Vitality of the Spores of Ustilago cucumis. 
To ascertain the vitality of the spores of this root-fungus under 
certain circumstances, I have experimented with them in the 
following manner : — 
The full-grown nodules found on the roots were dried gradually 
by artificial heat. These dried nodules were mixed, in a porcelain 
mortar, with 15 grammes of calcium sulphate and calcium carbonate 
(these minerals constituting the principal ingredients in the dust of 
the atmosphere). The mixture was then placed in a small oven and 
kept at a temperature of 35° C. (dry heat) for one, two, three, four, 
and six months. After the lapse of one month, the spores developed 
the disease on a sterilised seedling growing in the culture solution. 
The same remark applies also to portions of the mixture taken at 
intervals of two, three, and four months, — they had all the power of 
inoculation, only the period of “ incubation ” varied. After being 
dried up for six months at a temperature of 35° C., the vitality of 
the spores was completely destroyed, for no growths have made 
their appearance in a large number of seedlings placed in the most 
favourable circumstances for the growth of this fungus. 
From this part of the investigation it will be gathered that the 
spores of Ustilago cucumis are capable of being dried up in the dust 
of the atmosphere for several months without losing their vitality. 
Monday, 2nd July 1888. 
Pkofessoe CHEYSTAL, Vice-President, in the Chair. 
The following Communications were read : — 
1. On Fossil Fishes from the Pumpherston Oil Shale, with 
Exhibition of Specimens. By Ramsay Traquair, F.E.S. 
* See also his paper in the Journal de V Agriculture, Sept. 1887. 
