| 
—_— — ae ea Fe 
DECEMBER 25, 1913] 
ammonium humate can supply the nitrogen need of | 
plants if soluble phosphates and potassium salts are 
present in the culture solution. 
Mr. W. N. Jones gave an account of his investiga- 
tions on anthocyan formation. Coloured petals of 
stocks, &c., soaked in 95 per cent. alcohol became 
colourless, but regained their colour when transferred 
to water. 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 deter- 
mines which way the pigment reaction shall go. It 
also appears that considerable quantities of reserve 
“raw material’? occur in petals from which pigment 
can be produced. The darkening of many flowers on 
fading is explicable on the assumption that this raw 
material comes into action. 
Dr. E. M. Delf read a paper on the transpiration of 
sclerophytes. 
The Nature of Life. 
Prof. J. Reinke, of Kiel, dealt with the subject of 
the nature of life. In the period preceding the pre- 
sent the dogma prevailed that the phenomena of life 
ought to be interpreted merely mechanically. In still 
older times, people believed a vis vitalis to be active 
in the organism. Now the doctrine has arisen that 
life is only a complicated example of the processes 
predominant in lifeless nature; and physiology then 
becomes the chemistry and physics of organisms. 
Prof. Reinke, for his part, refused to adopt either 
the exclusively vital or the exclusively mechanical 
dogma. Life has its own laws, though this view 
does not exclude the fact that physico-chemical laws 
reign in the elementary processes of a living body. 
Fungi. 
Dr. O. V. Darbishire described the development of 
the apothecium in the lichen Peltigera. The early 
stage of the ‘fruit’? is found amongst the young 
marginal hyphe. Certain cells arise, which at first 
are uninuclear, but which become multinuclear. 
Fusions with neighbouring cells are common; but no 
transference of nuclei has been observed. No coiled 
carpogonia can be distinguished. The multinuclear 
condition seems to be due to simultaneous nuclear 
divisions in the cells, and not to any passage of nuclei. 
Long, unbranched, multicellular hyphe grow towards 
the cortex, whilst nuclear division is still active. 
These appear to be functionless trichogynes, and 
gradually disappear. Certain of the large cells—the 
‘“‘ascogonia’’—now grow out, and the nuclei formed 
by simultaneous division—female nuclei—pass into the 
ascogenous hyphz in pairs. From these the asci 
appear to derive their first nucleus in the usual way. 
Mr. S. P. Wiltshire spoke on the biology of the 
apple-canker fungus (Nectria ditissima), a genuine 
wound parasite. The chief means of inoculation in 
nature are injuries made by frost and by the woolly 
aphis (Schizoneura lanigera). The relatively immune 
varieties of apple may be readily infected through 
suitable injuries. 
Miss M. L. Baden described the conditions necessary 
for the germination of the spores of Coprinus ster- 
quilinus. She arrived at the conclusion that in some 
way bacteria are necessary for the germination of the 
spores of this fungus; and suggestions were made 
as to the way the bacteria are of benefit from this 
point of view. 
Miss E. M. Poulton gave an account of the structure 
and life-history of Verrucaria, an aquatic lichen. She 
showed how the structure of the thallus changed with 
advancing age, and how the ascospores underwent 
simultaneous germination within the perithecium, the 
tufted mass of mycelium thus produced being expelled 
into the water, and forming an efficient trap for the 
capture of the floating green unicellular Algz. 
NO. 2304, VOL. 92] 
NATURE 
489 
Prof. A. H. R. Buller, of Winnipeg, read a paper 
on the organisation of the hymenium in the genus 
Coprinus. 
Algae. 
Prof. G. S. West gave an account of the structure, 
life-history, and systematic position of the genus 
Microspora. After pointing out that species of this 
genus were amongst the most abundant and widely 
distributed of fresh-water Algze, and that the con- 
troversy concerning its systematic position was mainly 
due to defective knowledge, an account was given 
of its cytology and reproduction. The zoogonidia 
invariably possess two cilia, and there appear to be 
two distinct methods by which they may be liberated, 
with various intermediate conditions. The aplano- 
spores and akinetes were fully discussed, and the con- 
clusion arrived at that Microspora would be _ best 
placed in the family Microsporacez of the Ulotrichales. 
Prof. G. S. West and Miss C. B. Starkey had a 
paper on Zygnemu ericetorum and its position in the 
Zygnemacez. It was shown that published accounts 
of the cytology of this common Alga are all erroneous ; 
also that its conjugation, as observed in West Indian 
examples, is quite normal. The genus Zygogonium 
of Kiitzing (1843) cannot be accepted as of any value, 
and the Zygogonium of De Bary (1858) and Wille 
(1897, 1909), 1s based upon De Bary’s figures of two 
apparently monstrous conjugating examples. 
Dr. E. M. Delf gave an account of an attached 
Spirogyra. 
Ecology. 
Prof. F. W. Oliver discoursed on the distribution of 
Suaeda fruticosa and its réle in the stabilising of active 
shingle. Shingle beaches exposed to the sea are liable 
to travel landward during times of high tides when 
these are accompanied by onshore gales. S. fruticosa 
is the most effective plant in retarding this process, 
and is the most effective stabiliser of all British shingle 
plants. Valuable agricultural alluvial pasture is some- 
times greatly endangered by the movements of shingle 
beaches, and the suggestion was made that the 
‘‘ afforestation ’’ of certain shingle beaches by S. fruti- 
cosa was a matter of practical importance. 
Mr. P. H. Allen outlined a botanical survey, which 
some botanical students at Cambridge have under- 
taken, of the maritime plant formations at Holme, 
Norfolk. The area is characterised by (1) a salt 
marsh, with Armeria maritima, Statice Limonium, S. 
binervosum, S. vellidifolium, Cochlearia anglica, Sali- 
cornia perennis, S. disarticulata, Atriplex portula- 
coides, and other halophytes; (2) a shingle bank, with 
Suaeda fruticosa and Frankenia laevis; and (3) sand- 
dunes, with Ammophila arenaria, Elymus arenarius, 
and Hippophaé rhamnoides. The mapping out of the 
area was begun by chaining out a base line seven 
furlongs (ca. 1-4 km.) in length. At each furlong 
offsets were chained out to the cultivated land on the 
one side and low-water mark on the other. The 
mapping in of the plants in the smaller areas thus 
obtained was done with the plane table on a scale of 
80 in. to the mile (1: 792). Work on the analysis of 
the soil and the soil-water is being carried on. It is 
hoped that light will be shed on some of the problems 
of plant-distribution, and that a detailed record of 
the succession of changes occurring over the area will 
also be obtained. 
Mr. A. R. Horwood presented his ideas with regard 
to the influence of river-development on plant-distribu- 
| tion. 
Miss W. H. Wortham described some features of 
| the sand-dunes in the south-west of Anglesey. The 
fixed dune association is a Caricetum arenarieae, 
which forms a close sward. The shifting dunes, with 
Ammopfhila arenaria and Euphorbia paralias, alternate 
j With embryonic stages of dune-marsh, with Salix 
