The London Botanical Society. 
20/ 
THE LONDON BOTANICAL SOCIETY. 
rMHE October meeting of this Society was held on Friday. 
I October 30th, at the Royal College of Science, at 4.15 p.m,, 
Professor Oliver in the Chair. 
Dr. Scott shewed some lantern-slides illustrating the germi¬ 
nation of the spores within coal-measure fern-sporangia. Many of 
the details of germination, exactly resembling those of recent fern- 
spores, were extremely well shewn. The sporangia could not he 
definitely assigned to any known genus of coal-measure fern. 
Mr. Boodle exhibited some striking results in the local pro¬ 
duction of anthocyanin in the leaves of Rheum. The red pigment 
was confined to certain areas of the leaf supplied by veins which 
had been accidentally severed. A similar result was obtained 
experimentally by dividing the midrib of the leaf of the Evening 
Primrose (CEnothcra biennis) about the middle of its course, when 
the whole distal part of the leaf beyond the cut became coloured 
red, the leaf of course having been left on the plant. The effect 
was only obtained when the affected part was exposed to full day¬ 
light. Mr. Boodle found that the different varieties of QLuotlieva 
were not equally good for shewing the effect. The explanation 
suggested was that the interruption of the channel by which the 
carbohydrate products of assimilation are normally removed from 
the mesophyll caused an alteration of glucose or anallied substance 
into the pigment. This is in harmony with the work of Overton 1 in 
which the occurrence of anthocyanin was found to be associated 
with an increased sugar content; and with that of Linsbauer, 2 who 
concluded that in cases of mechanical wounding the red colouration 
can be traced to a lowering of the facility of conduction of certain 
plastic materials. Mr. Boodle is publishing an account of his 
results in the next number of this journal. 
Professor Farmer suggested that it would be important to test 
the effect of different rays of the spectrum upon the production of 
the red colour under these circumstances. 
Mr. Boodle also exhibited some specimens of the flowering 
shoots of the Hollyhock in which the basal leaves shewed a tendency 
to become branched, or even compound. He pointed out that 
in the allied Adansonieae the leaves aer normally compound, and 
suggested that his observation might perhaps indicate an ancestral 
type with compound leaves. 
1 Jahrb. f. wiss. Hot. 1899. 
? Oesterr. bot. Zeitung, 1901. 
