108 REPORTS ON THE STATE OF SCIENCE—1914. 
The Study of Plant Enzymes, particularly with relation to 
Oxidation.—Third Report of the Committee, consisting of 
Mr. A. D. Hatut (Chairman), Dr. E. F. ARMSTRONG 
(Secretary), Professor H. E. Armstronc, Professor F. 
KEEBLE, and Dr. E. J. RUSSELL. 
Work is being continued along the lines indicated in former reports. 
The further investigation of the distribution of oxydases (per- 
oxydase) in the flowers of Primula sinensis has led to the discovery 
that in certain white-flowered races which breed true to whiteness 
the peroxydase has a definite zonal distribution. Such white-flowered 
races, when crossed with coloured forms, yield in the F, generation 
a certain number of plants having flowers which exhibit a colour pattern 
of a similar zonal character. Hence this pattern may be referred to 
a lack of uniformity in distribution of the peroxydase constituent of 
the colour-forming mechanism, not of the chromogen. This investiga- 
tion has involved the study of a large number of plants of known 
genetic constitution and of their progeny; it may be expected that 
eventually it will throw light on the phenomena of flaking and colour 
pattern in flowers. 
Concurrently with the study of the distribution of oxydases in 
plants, the occurrence of reductases has also been investigated, using 
this term as a general expression for substances which exert a re- 
ducing action. After many trials, partial success has been achieved 
by the discovery of agents indicative of such compounds, and evidence 
of the zonal distribution of reductases has been obtained. 
A general summary of the bearing of chemical observations on 
genetic constitution and the relation of enzymes to colour inheritance 
in plants was given before the Linnean Society in March, when it 
was particularly pointed out that, in life, interaction takes place 
between substances in pairs, the one being oxidised and the other 
reduced. Consequently the same interaction is often recorded whether 
oxydase or reductase be indicated by the agent used. This conception 
materially simplifies the study of the oxidative changes in plants. 
The formation of red pigments from yellow flowers by reduction 
and subsequent oxidation described in the last report has been further 
studied during the year. To elucidate the precise nature of the change 
by working with material of known structure, the experiments were 
extended to quercetin, which has been reduced under a variety of 
conditions. As a rule, colourless compounds are formed which become 
red on exposure to the air or on the addition of hydrogen peroxide. 
The problem has been investigated independently at Reading by 
A. EK. Everest (‘The Production of Anthocyanins and Anthocyanidins,’ 
Proc. Roy. Society, 1914, 87 B. 144), who finds that the change from 
yellow to red may be effected by reduction alone, and that reduction 
takes place quite readily without the occurrence of hydrolysis. As 
Willstatter has now directed his attention to the chemical structure 
of the anthocyanic class of pigments, it is not proposed to continue 
the research in this direction. 
A study has been made of the rate at which various carbohydrate 
solutions are able to decolourise methylene blue in alkaline solution, 
