’ 
490 
NATURE 
[DECEMBER 25, 1913 
repens. Dunes of S. repens occur, and have a two- 
fold origin: (1) the inundation of a dune-marsh with 
sand, and (2) invasion of Salix seedlings. The ulti- 
mate association of the marsh of S. repens is a 
Callunetum vulgaris, and of the dunes an Agrosti- 
detum vulgaris. 
Genetics. 
Dr. R. R. Gates brought forward some evidence to 
show that mutation and Mendelian splitting are 
different processes. He maintained that definite 
evidence has been obtained to show that some of the 
mutations in GEnothera are not due to recombinations 
of Mendelian characters, as some biologists have 
assumed, but to irregularities in meiosis, which lead 
to changes in nuclear structure. 
In connection with the visit of Sections D, K, and 
M to the Burbage Experimental Station for Applied 
Genetics, Major C. C. Hurst read a paper on the 
inheritance of minute variations in garden races of 
Antirrhinum. The garden variety, ‘“ Aurora,’’ breeds 
true to its bushy habit of growth, its scarlet lips, and 
its ivory throat; but individual plants show slight 
differences in habit, precosity, and in size and colour 
of flowers. Experiments on these, in conjunction with 
others on sweet peas and culinary peas, show that 
many. presumed unit-factors can be analysed into 
several subfactors which themselves behave as units. 
It is also evident that these minutely continuous 
variations are strictly discontinuous in their inherit- 
ance. 
Miscellaneous. 
Prof. F. E. Weiss recorded and described a case 
of juvenile flowering in Eucalyptus globulus. 
Dr. A. S. Horne described the variations in the 
flower of Stellaria graminea. 
The semi-popular lecture was this year delivered by 
Prof. W. H. Lang. The subject, ‘“‘Epiphyllous Vege- 
tation,’ dealt with the different forms of plant-life 
which pass their lives on the surface of the leaves of 
tropical plants, and attracted a large and interested 
audience, ; 
Colonel H. E. Rawson described his experiments 
and observations on the variation of the structure and 
colour of flowers under insolation. The paper was a 
continuation of one communicated to the section in 
1908. His method was to shade off with a perfectly 
opaque screen all direct rays of the sun for certain 
selected intervals of daylight, while admitting all the 
diffuse light possible. By this means, it is claimed, 
many colour and other forms were produced. Colonel 
Rawson maintained that his experiments, which have 
now extended over eight years, definitely point to a 
connection between the variations of colour and 
structure and the sun’s altitude, both seasonal and 
diurnal: and he suggested that solar rays of different 
refrangibility are transmitted through the atmosphere 
at different altitudes. 
Preservation of the British Flora. 
Mr. A. R. Horwood introduced the subject of the 
preservation of the British flora, which has come into 
some prominence again during the past year or two. 
He pointed out that there are some factors which tend 
to the extirpation. of certain British plants, and 
are difficult to control except in special ways. He 
asked for information as to the extent of the effect of 
these factors, and for suggestions for combating their 
effects. Factors mentioned were drought, drainage, 
cultivation, building operations, and the spread of golf 
courses. He added his opinion that an Act of Parlia- 
ment was required to deal effectively with some 
aspects of the general problem. There was some 
disagreement among the speakers who followed as to 
the best means of attaining the desired end. 
NO.- 2304, VOL. 92] 
The committee of the section passed a, resolution 
expressing. sympathy with the general object, but 
withholding their support from..any proposal which 
might tend to affect the present Jaw of trespass. .— - 
Joint Meetings. 
Two meetings were held jointly with other sections. 
The first was held in conjunction with the newly 
formed Agricultural Section, when some problems in 
barley production were discussed. The second was 
held in conjunction with the Zoological and Physio- 
logical Sections, when Prof. B. Moore introduced a 
discussion on the synthesis of organic matter by 
inorganic colloids in the presence of sunlight, this 
subject being considered in relation to the origin of 
life. Fuller accounts of these joint meetings are given 
in the reports of these sections. 
Exhibits. 
A series of exhibits of Alga and fungi were 
arranged by Prof. West in the Botanical Laboratory. 
Among the Alga were twenty selected Caulerpas, to 
show how the different species simulate the Various 
types of habit found in higher plants; some beautiful 
examples of Lithothamnion, Lithophyllum, and other 
stone Algz; microscopical preparations of various 
Algze, including conjugated Desmids, showing all 
types of Zygospores, Euastropsis Richteri, akinetes of 
Microspora floccosa, the largest known Desmid (Clos- 
terium turgidum subsp. giganteum), Tetraspora gela- 
tinosa, showing the pseudocilia, and the following 
Volvocaceaze—Platyodorina caudata, Pleodorina illinois- 
ensis, Pleod. californica, Volvox africanus, and V. 
Rousseletii. 
The fungi included numerous Deuteromycetes, 
Pyrenomycetes, Discomycetes, Uredinez, Ustilaginez, 
and Hymenomycetes, mounted for class purposes; a 
series of dried specimens of the Polyporeze; specimens 
of Batarrea phalloides, Rhoma pigmentivora; and 
cultures of Sigmoideomyces clathroides, and of a 
species of Sepidonium. 
Living and fixed specimens of the giant sulphur 
bacterium, Hillhousia mirabilis, were also on view, 
and a series of about fifty species of Mycetozoa 
(Myxomycetes) from the midland counties, — 
&c. 
More or less informal excursions were held, the 
following places being visited by some members of 
the section :—(1) Hartlebury Common, a sandy heath 
with Calluna vulgaris, Ulex Gallii, and Drosera 
rotundifolia in the bogs. 
summer, the spring ephemerals (including some sub- 
maritime species) were invisible. (2) Sutton Park, a 
great stretch of semi-natural vegetation of heaths 
Excursions, 
alternating with oak woods and marshes, the whole 
on sandy and gravelly soils. The heaths showed wide 
expanses of Aira flexuosa, Molinia caerulea, Ulex 
Gallii, U. europaeus, Calluna vulgaris, and a little 
Empetnem nigrum. The woods were dominated by 
Quercus Robur, associated with Betula pubescens and 
Tlex aquifolium. Some societies of the last-named 
species were unusually fine. (3) Wyre Forest, an 
extensive natural forest of Quercus sessiliflora, asso- 
ciated with Betula alba. Locally, Carex montana 
was an abundant member of the ground vegetation of 
the forest. 
The excursion to the Burbage Experimental Station 
for Applied Genetics, held jointly with the Agricul- 
tural and Zoological Sections, is referred to in the 
report of the latter section in Nature of Novem- 
ber 27,(p. 389). 
The sectional dinner was held on the Saturday even- 
ing, when nearly eighty members of the section were 
present. 
At this late stage of the. 
