TRANSACTIONS OF SECTION K. 113 
been affected, and changes of colour and structure produced which can be 
reproduced in other individuals. 
It is suggested that an explanation is to be found in the fact that solar rays 
of different refrangibility are transmitted through the atmosphere at different 
altitudes. Many instances have occurred of low sun modifying crimson colouring- 
pigments so that the yellow predominated, and of the highest sun available in 
these islands promoting the purple and violet pigments. Some red pigments, 
but not all, can be intensified by intermediate sun. Should these results be 
confirmed by independent investigators, they would afford a clue to many obscure 
problems of which correlated variation and variation under domestication may 
be specially mentioned. 
7. Some Investigations in Anlhocyan Formation. 
By W. Netson Jones, M.A. 
A series of papers dealing with the problems of pigmentation in plants have 
recently been published: the present paper is concerned with some points of 
special interest that have arisen in this work. 
1. Coloured petals of stocks, &c., soaked in 95 per cent. alcohol become 
colourless; transferred to water they regain their original colour. 
It is believed that a pigment-producing mechanism and also a reducing body 
are present in the petals. The amount of water in the cells determines which 
way the pigment reaction shall go: in strong alcohol (95 per cent.) reduction 
occurs and the petals become colourless; in weak alcohol or water oxidation 
takes place, resulting in the production of pigment. It appears, further, that 
considerable quantities of reserve ‘raw material’ occur in some coloured 
flowers (e.g., stock) from which pigment can be produced. The darkening of 
many flowers on fading is explicable on this hypothesis as being due to this 
‘raw material’ coming into action. % 
2. Benzidine gives a blue colour with a solution of oxidase prepared from 
bran (bran+water+H,0.). JMJethyl quinol gives no reaction with this oxidase 
solution alone, but on the addition of a trace of benzidine becomes oxidised 
to a red colour. Methyl quinol thus behaves towards benzidine as an epistatic 
member of a colour series (e.g., in Primula sinensis) to a hypostatic—that is, 
it is able to manifest itself only if the hypostatic member is present. (In this 
reaction the benzidine probably plays the part of a carrier of oxygen to the 
methyl quinol.) 
Although it is dangerous to argue from analogy, in default of other evidence 
it would seem likely that the colours of an epistatic series were due to different 
substances behaving as methyl quinol above, rather than to the action of 
specific oxidases. 
MONDAY, SEPTEMBER 15. 
The following Papers were read :— 
1. The Development of the Apothecium in the Lichen Peltigera. 
By O. V. DarBisHirE. 
Pycnidospores, or spermatia, are very rare indeed in this genus, and their 
occurrence seems to be confined to a few species, and is even here very rare. 
Yet we find that in certain species apothecia are formed in great numbers. 
Fuenfstueck and Baur have examined Peltigera, and without going into nuclear 
details the latter described it as a case of apogamy. 
The following additional details have been made out. Growth of the vegeta- 
tive thallus is mainly marginal, though new hyphe may be intercalated be- 
tweeu the old upright hyphe of the cortex. It is amongst the young marginal 
hyphe that we find the beginning of the fruit. Certain cells of the medullary 
1 ¥. Keeble, E. Frankland Armstrong, W. Neilson Jones. The Formation of 
Anthocyan Pigments in Plants, Parts iv, and vi, 
