138 
That Prof. McAlpine has made a definite and valu- 
able contribution to our knowledge of this patho- 
logical problem will appear presently, but this is only 
an added reason why he would have done well to 
make it perfectly clear that the main problem still 
remains to be resolved. To conclude that the 
“immediate cause ’’ of the disease is ‘the concentra- 
tion of the cell sap’’ (p. 75) is not to discover a 
cause, but to use words the meaning of which is 
at least as obscure as the nature of bitter pit. _More- 
over, if quick-acting nitrogenous manures, which lead 
to sappy growth, encourage bitter pit, how may that 
disease be attributed to concentration of sap? 
Perhaps the most valuable part of Prof. McAlpine’s 
studies is that which demonstrates the possibility of 
preventing the outbreak of bitter pit in cold-stored 
apples. As the result of experiment, he shows that 
if apples be stored at a temperature of about 30° or 
32° F., and if fluctuations beyond these limits be 
prevented, no bitter pit manifests itself during a 
period sufficiently prolonged to transport the fruit 
from Australia to Europe. ‘This is a great gain, and 
the practical results accruing from it should not only 
pay for the cost of this elaborate investigation, but 
encourage the Commonwealth to promote further 
investigations into the origin of the disease. 
A point of some interest on the scientific side of 
the problem is the fact that starch persists in the 
broken-down tissue of the pitted region of the apple 
pulp, whence it is concluded that the incipient but 
invisible stage of the disease occurs in the pre-ripen- 
ing phase, or at all events during the phase in which 
starch gives place to sugar. This is plausible, but 
the opposite view is not precluded that the starch of 
the bitter pit arises as a result of a reconversion of 
sugar. In favour, however, of the view that bitter 
pit develops, although it is mot apparent, at an early 
stage is the evidence obtained by subjecting suspected 
apples to X-rays, as a result of which it is claimed, 
and the claim is supported by photographs, that pro- 
spective pit areas appear on the radiographs. 
Prof. McAlpine is hopeful that the loss due to 
bitter pit may be ultimately prevented by breeding 
pit-resistant varieties. It is a work worth under- 
‘taking, but nevertheless is not to be undertaken 
lightly, for it may prove a long business. ae 
GEOLOGY AT THE BRITISH ASSOCIATION. 
Vie president, Prof. W. S. Boulton, delivered his 
address on Wednesday, September 6, to a good 
audience, and was followed by Prof. G. A. Lebour. 
who described: the general geology of the rocks round 
Newcastle, 
The Permian formation, which forms such a large 
part of the surface geology in the neighbourhood, 
received special treatment at the hands of Dr. D. 
Woolacott, who has made it a detailed study, and 
brought order out of the complicated bedding. He 
shows that the Middle Permian Beds consist of a 
fossiliferous, unbedded rcef formation, which ran 
parallel to the coast of the Permian sea, and on each side 
of which are well-stratified, unfossiliferous limestones, 
which were formed in waters permeated with calcium 
sulphate, which afterwards formed gypsum beds. The 
concretionary formations found in the various beds 
were lucidly dealt with. 
During the meeting Dr. Woolacott took the geo- 
‘logists to see several typical sections of the Permian 
beds, and exhibited interesting evidence in proof cf his 
contentions. 
The important questions of the underground mapping 
-of prominent coal seams were dealt with by Mr. Wick- 
NO. 2451, VOL. 98] 
NATURE 
[OcToBER 19, 1916 
ham King in his plexographic model of the South 
Staffordshire thick seam, by Dr. G. Hickling in 
diagrams of the Black Mine coal of Lancashire, and 
by Prof. W. G. Fearnsides in maps of the Barnsley 
bed. 
In the afternoon a_ special goint meeting with 
Section K was held to receive the report of the Re- 
search Committee appointed to investigate the Old 
Red Sandstone of Rhynie, Aberdeenshire, and to hear 
a paper by Dr, R. Kidston and Prof. W. H. Lang 
describing the very interesting fossil remains found in 
that deposit. The present paper dealt only with one 
of these, Rhynia gwynne-vaughani, which is the oldest 
known peat. The plants, which were rootless and leaf- 
less, and grew crowded together, consisted entirely of a 
system of cylindrical stems, attaining a height of 8 in. 
or more, and ranging in diameter from 1 to 6 mm. 
The stems bore small hemispherical projections, from 
some of which lateral branches were developed. The 
aerial stems had a_ thick-walled epidermis with 
stomata, a cortex, and a simple central cylinder. 
Large cylindrical sporangia, containing mumerous 
spores, were found in the peat. They were evidently 
borne terminally on some of the leafless aerial stems. 
On Thursday there was an important joint discus- 
sion with the members of Section B, which dealt with 
the investigation of the constitution and classification 
of coal. A combined geological and chemical study 
was recognised by all speakers as an essential to 
success. .There was also general agreement as to the 
need for more systematic and careful selection of 
samples, for the separate investigation of the various 
constituent elements of seams, and for the microscopic 
examination of the specimens analysed. The great 
national importance of the work was also emphasised. 
The discussion was onened by Prof. G. A. Lebour, 
followed by Prof. W. A. Bone, Prof. P. F. Kendall, 
Prof. P. P. Bedson, Dr. J. T. Dunn, Mr. D. Trevor 
Jones, Dr. Marie C. Stopes, Dr. G. Hickling, Prof. 
W. G. Fearnsides, and Prof. W. Boyd Dawkins. 
At the close of the discussion Dr. J. W. Evans 
gave a suggestive description of a method of repre- 
senting geological formations and structures in black 
and white on maps. Mr. Leonard Hawkes described 
the Tertiary acid volcanic rocks of Iceland. In places 
this acid series is at least 2000 ft. in thickness, and 
consists of tuffs, sphzero-like liparites, and obsidians, 
The eruptions were similar to those of post-Glacial 
times. The uneroded character of the liparite lavas 
shows how rapidly the successive basalts which sub- 
merged them were poured out. Since the close of the 
Tertiary volcanic period enormous denudation has ob- 
tained, and the varying resistance offered to erosive 
agents by acid and basic rocks has produced remark- 
able topographical effects. 
Dr. Alexander Scott gave the results of an exten- 
sive examination of the Arran pitchstones, describing 
four groups varying from non-porphyritic glasses with 
abundant microlites of hornblende, to a more basic 
type with scarce phenocrysts, but with abundance of 
pyroxene microlites. An attempt had been made to 
determine the cooling histories from an-examination of 
the field relations and the microscopic structures of 
the various types, and also to indicate the conditions 
which were responsible for such a large development 
of slassy intrusive rocks. 
On Friday a joint meeting ws held with Section E, 
to hear a paper by Dr. Albert Wilmore on_ the 
Northern Pennines. The structure of the range and! 
its gaps with the intervening rock-blocks were de- 
scribed. _ The effects of the fault and fold svstems on 
the scenery were dealt with, and many interesting 
problems which still leave scope for careful investiga- 
tion were pointed out. 
