382 SECTIONAL TRANSACTIONS.—K. 
The seasoning of wood is described and the various methods of seasoning 
and the moisture content requirements for different purposes. 
Under certain conditions wood is subject to decay—probably one of its 
major defects when used for industrial purposes. Methods of preservation 
are described. In certain cases these may consist of details of construction. 
The most important methods are, however, treatment with toxic chemicals. 
The different types of chemicals and the methods of applying are described 
for the different industrial purposes for which wood is used. 
AFTERNOON. 
Prof. W. SEIrRiz.—The structure of protoplasm (2.15). 
Mr. T. A. Oxtey.—The influence of light and temperature on growth (3.0). 
Lemna minor has been grown under carefully controlled conditions of 
light and temperature, the temperatures ranging from 10° to 35° C. and the 
light intensities from 80 foot-candles to 1,600 foot-candles. Growth rate, 
dry weight per frond, and area per frond have been measured under each 
of the forty-eight sets of conditions. From the results obtained the inter- 
action of light and temperature on plant growth has been analysed and 
conclusions drawn which may be applicable to green plants generally. 
Notably, evidence has been obtained to show that light does not control 
growth solely, or even chiefly, by limiting the amount of assimilate formed, 
but that there is some photochemical reaction other than assimilation which 
controls growth. 
Dr. R. E. Cuapman.—The absorption of water vapour by the aerial parts of 
Egyptian desert plants (3.30). 
The experiments described in this paper indicate that some plants of the 
Egyptian desert can, in an atmosphere of high humidity, increase in weight 
(presumably by the absorption of water vapour by their aerial organs). In 
the Egyptian desert, owing to the great difference between day and night 
temperatures, it is often found that during the night the air humidity 
approaches saturation even in summer, and hence may be the source of an 
appreciable part of the plant’s water supply in plants like Reaumuria histella, 
which have salt crystals on their leaves. ‘These crystals apparently form 
part of the mechanism of absorption of water vapour, as without them the 
plants do not increase in weight in atmospheres of high humidity. 
In this way about one-sixth of the plant’s loss by transpiration may be 
replaced by absorption of water vapour at night. 
Mr. W. A. CLarK.—The effects of carbon monoxide on tomato plants and 
potato tubers (4.0). 
Tomato plants subjected to a 2 per cent. concentration of carbon monoxide 
gas in a moist chamber produce stem-borne roots. The anatomy of such 
roots is dealt with. 
Halved potato tubers were treated in a similar manner to the tomato 
plants. The gas first caused proliferation of the lenticels, but later, pro- 
liferation takes place freely from the tissues underlying the periderm. 
Abnormal development of the shoots also occurs, the bases of the shoots 
becoming swollen and covered with proliferating lenticels. 'The gas also 
hinders cork meristem formation at the cut surface. 
No roots were induced from mature tubers, but in the case of entire 
potato plants subjected to the gas, roots appear to arise from the daughter 
