14 * 
YORKSHIRE NATURALISTS’ UNION : 
BOTANICAL SECTION. 
This section met on February nth, and is again indebted to Prof. 
Priestley and the authorities of the Leeds University for the use of the 
rooms there, and also to Mrs. Priestley and Mrs. Grist for the very 
welcome tea they provided. 
Prof. Priestley, in the chair, gave a hearty welcome to Dr. T. W.. 
Woodhead at this, the first meeting during his year of office as President, 
Mr. J. W. H. Johnson’s paper, dealing with the influence of last 
summer’s drought on the selection of flowers by honey bees, commenced 
with general details of their work among nectar, pollen and propolis. 
Then a description of the variation of honey during a normal season, from 
the limpid clover honey to the stiff er honey later in the year. Maximum 
production is found during warm, muggy weather. Nectar is lacking in 
dry times and washed out in wet, and the bees do not work in heavy 
rain. In 1920, the saturated soil of January and February persisted,, 
more or less, into late summer; but in 1921 the ground quickly dried, 
and the flowering seasons of the various plants were intense, but short.. 
The heavy rain of August helped the flowering of the labiates of this part 
of the year, and produced a type of honey flavoured with mint, a fact: 
noted from widely separated districts. 
Dr. Woodhead and Miss Bates dealt with the same area of moors- 
near Marsden, the first dealing with flints from under the peat, and 
mentioning very interesting finds by Mr. Buckley, of Greenfield, and. 
others ; Miss Bates taking the subject of buried timber. 
Mr. F. E. Milsom gave a resume of the many theories on the subject 
of Oil Bodies of Liverworts. These highly refractive bodies, so charac- 
teristic of the cells of Alicularia scalaris as to be deemed a useful character 
in determining species, are in very varied size, form and number present 
in the tissues of many Liverworts. 
The suggestions of earlier workers as to their formation were : — 
(1) By the union of many small oil drops in the cell. Pfeffer, 1874.. 
(2) By the formation in elaioplasts. Wakker, 1888. 
(3) Oil is distributed throughout a protein stroma, v. Kuster, 1894.. 
(4) Garjeanne (1903) showed they originate in very young cells at 
the growing point, by the secretion of oil in vacuoles, probably 
in a semi-fluid matrix, separated from the cell sap by a living 
protoplasmic wall ; once formed, the oil bodies persist until the- 
death of the cell, a fact that suggested an excretory substance- 
in contradistinction to the elaioplasts, which are metamorphosed 
chlorophyll grains and are reabsorbed. 
The chemical composition appears to be a fatty oil associated fre- 
quently with an essential oil. Mr. Milsom showed photomicrographs of 
the oil bodies in Alicularia scalaris, and a sample of viscid dark-coloured 
oil extracted from this plant. 
Dr. Pearsall dealt with the change of wood type by a change of habitat ; 
starting with a limestone area, and taking the head of a stream with 
steep cliffs and scree with a shrub growth, to a more open type, as Ling 
Ghyll, where the soil is more modified, and the wood is some 60% Elm, 
30% Ash ; next, the broader valley, as the lower part of Thornton 
Ghyll, Ingleton, where 50% Ash, 20% Elm and 20 to 40% Oak is found,, 
and from this gradually to where Oak becomes the chief factor. 
Dr. Ewing’s paper on an indigenous Pine forest of North Scotland 
supplemented the previous communication. He showed clearly how 
Calluna under Pines stopped the development of seedling pines, and 
also how the pine wood developed through lichens and mosses on a bare 
stoney area. 
Mr. Sheppard’s communication, dealing with recent records of birds, 
etc., will appear in these pages, and adds another interesting chapter to 
the story of Yorkshire peat. — Chris. A. CheethAm. 
1922 Apl. 1 
