The British Association at Dundee. 
367 
Biochemical Papers. 
Professor Armstrong gave a further account of his work on 
chemical variation in Lotus comic Hiatus. In some forms the action of 
chloroform vapour on the fresh plants indicates the presence of a 
glucoside by a change in colour. Plants from the South of England 
almost invariably showed the presence of the cyanophoric glucoside, 
while others collected in Ayrshire and also in Norway gave no 
reaction. Some plants give only a faint reaction, so that the 
glucoside may be regarded as latent; the intensity of the reaction 
has been, in the case of many plants, noticeably less this year. This 
suggests that the differences observed in the chemical constitution 
of the plants may be chiefly due to the conditions under which they 
have grown. 
Dr. E. F. Armstrong gave an account of the work he has 
recently done in conjunction with Professor Keeble, on the 
chemistry of flower pigmentation. Anthocyan pigments in flowers 
are thought to be produced by the action of oxydases on chro¬ 
mogens, the latter being formed by the hydrolysation of glucosides. 
The oxydase can be regarded as consisting of two parts, a peroxy- 
dase and an organic peroxide, and in some flowers the peroxydase 
only may be present. Keeble and Armstrong have found that by 
the use of u-naphthol or benzidine the oxydases present in the 
flower can be localised, and further the presence of the peroxydase 
may be often be located. The former reagent is always confined to 
picking out the veins of the corolla, while the benzidine reaction is 
exhibited by the superficial cells. 
The reagent shows that oxydases are produced when the flower 
petal is wounded, for example by pricking, but these are probably 
different from the pigment oxydases. When plants are kept in the 
dark an increase in the amount of oxydase is observed. 
Mr. W. N. Jones read an interesting paper on the distribution 
of oxydases in white flowers. In these the absence of colour is 
presumed to be due either to the absence of one or both of the 
pigment producing bodies, viz., chromogen and oxydase or peroxy¬ 
dase, or to the presence of an inhibitor checking the action of the 
oxydase or peroxydase. Investigation points to the existence of 
the following types of white flowers:— 
(a) . Those in which a chromogen or an oxydase both occur, 
but from some cause, such as their localisation in different cells, do 
not react together. On treating these with alcohol they go slightly 
brown, as they do when benzidine is used. 
(b) . Those containing chromogen and peroxydase, but re¬ 
quiring the addition of hydrogen peroxide to produce a reaction. 
(c) . Those containing a peroxydase but no chromogen body, 
these give a reaction only when benzidine is added together with 
hydrogen peroxide. 
A chromogen can be extracted from the flowers of Lychnis 
coronaria, which may be used instead of benzidine in testing the 
last group of flowers. 
Dr. Eyre read papers on the enzymes of Linnm and on its 
variation with locality. The yellow flowers of Linaceaj contain no 
