SECTIONAL TRANSACTIONS.—K. 551 
to their greater viability, and that one family there reported was exceptional 
in giving one-quarter doubles, as should the progeny of a plant freed from 
the pollen lethal. 
The close linkage between the pollen lethal and the factor for doubleness 
is due to selection acting automatically in the propagation of the ever- 
sporting lines, which has thus built up the ever-sporting character. 
AFTERNOON. 
Prof. N. G. BaLL.—The effect of nocturnal illumination on the subsequent 
opening of flower buds (2.0). 
The flowers of certain plants, Turnera ulmifolia var. elegans, Asystasia 
gangetica, Ipomea spp. and others, which normally open in the morning, 
are markedly affected when the buds are subjected to light during the pre- 
vious night. In buds which have been treated in this way, the petals, 
although they become elongated, may fail to diverge, and short-lived flowers 
may become withered while they are still in the closed condition. A some- 
what similar result is obtained when the buds are illuminated two nights 
before they are due to open, even if this is followed by normal conditions 
during the second night. 
In most species where this effect of light has been observed, the failure 
of the flower to open is correlated with a partial inhibition of the normal 
hydrolysis of starch in the petals. This inhibition is associated with a 
decrease in the diastatic activity of the cell-sap. 
In the case of flowers which react in this way, a comparatively weak 
illumination during the night is sufficient to prevent the buds from opening. 
When a screen which only transmits the red rays is placed between the light 
and the plant, the result is the same as it is with white light, but the infra- 
red rays alone do not have this effect. On the other hand, when buds 
are exposed during the night to the blue and violet rays only, even when 
the intensity of the light is considerably increased, they behave in a similar 
manner to those which have been kept in the dark and open normally. 
Dr. B. T. CRoMWELL.—Berberine in the metabolism of Berberis Darwinii 
(2.30). 
Experimental evidence leads to the deduction that the alkaloid 
berberine is a waste product of metabolism, and that it is produced in 
largest amounts when conditions favourable for protein breakdown are 
realised. Accumulation of the alkaloid in the root and stem bark takes 
place from year to year. Application of inorganic nitrogenous salts alone 
does not lead to increased alkaloid production, but if, in addition, glucose 
is supplied, or organic nitrogenous compounds, such as asparagine, are 
applied alone, rise in berberine content is observed. Light is an important 
factor in the synthesis, and all tissues growing in absence of light show high 
values. In shoots which have been grown for alternate periods in darkness 
and in light, only those regions which have made growth in absence of light 
exhibit high percentages of alkaloid. Withdrawal of essential elements 
leads to variations in yield. Under conditions of nitrogen starvation, 
alkaloid still accumulates : therefore it does not play the part of a nitrogenous 
reserve. Deprivation of calcium does not check berberine production, but 
withdrawal of potassium appears to inhibit synthesis. It is suggested that 
the alkaloid is synthesised from carbohydrate and protein residues. 
Excursion to Charnwood Forest. 
