516 
NATURE 
[JANUARY I, 1914 
yield large increases in the amount of ammonia and 
of nitrate. 
This was followed by a paper by Mr. Goodey 
describing his investigations on the protozoa of the 
soil. The first forms investigated were the ciliated 
protozoa, particularly Colpoda. Evidence was 
adduced to show that this organism probably exists 
in the soil as cysts, though it must have had some 
active existence some time because of the large num- 
bers in which cysts occur. Another investigation 
dealt with the effects of partial sterilisation on two 
old soils which had been stored in bottles for many 
years at Rothamsted, one since 1846 and the other 
since 1870. The 1870 soil behaves normally on partial 
sterilisation, giving an increase in bacterial numbers 
and also in ammonia and nitrate, showing. that the 
limiting factor present in ordinary soils was also pre- 
sent in this soil; amcebz and flagellates also occurred. 
The 1846 soil, however, behaved entirely differently 
and showed the phenomena of a soil already partially 
sterilised; there was no evidence of any limiting 
factor being present, and no ameebe, flagellates, or 
other protozoa could be found. 
In the discussion that followed Prof. Gamble ex- 
pressed the opinion that amoebz and flagellates could 
probably be found in an active condition in the soil 
although the ciliates probably were not. 
A third paper dealt with the nitrification in some 
pasture soils, and was presented by Mr. Gimingham. 
It is known that nitrification is reduced to a minimum 
in pasture soils rendered acid by the continued use of 
ammonium salts as manure, and an investigation was 
therefore made of a soil intermediate in character 
between the true moor and the true fen soil. This 
contains 30 to 40 per cent. of organic matter and only 
traces of carbonate, but the water is neutral in 
action. The soil was found to be capable of bringing 
about rapid nitrification of peptone, a remarkable 
feature being the great amount of action directly the 
peptone was added. Ammonium sulphate also quickly 
nitrifies, but the soil in this case takes on a feebly acid 
reaction, 
Prof. Bottomley described experiments in which 
peat was treated with certain aérobic soil bacteria, 
and then became converted into a_blackish-lookine 
powder of distinct manurial value. It was also stated 
that the substance conditioned fixation of nitrogen 
in the soil. 
A paper was presented by Miss Taylor on the life- 
history of Eriophyes ribis. When Ribis nigrum is the 
host-plant the embryonic true leaves of the bud are 
attacked by the mite and the bud develops into a 
‘“big-bud."” No injury is caused, however, to the 
foliage of the tree. The migration of mites from 
infested buds is carried out mainly by the wind. On 
the other hand, when Ribis grossularia is the host- 
plant the scales leaves of the bud only are attacked 
and no big-bud is formed. Apparently the mite cannot 
penetrate the true leaves of the bud, and injury is con- 
fined to the foliage. Distribution by wind is not 
general, migration being mainly due to the mite 
Fab es from the infested bud to the expanding 
eaves. 
Dr. Winifred Brenchley summarised ier investiga- 
tions on the weeds of arable land. On clay soils the 
weed flora is less rich in species than on light loam, 
and though several plants have a distinct preference 
for heavy land no species can be said to be sympto- 
matic of clay, occurring on such soils and nowhere 
else. Sandy soils possess a much more characteristic 
weed flora, as they are colonised by a great diversity 
of plants, a number of which are distinctly associated 
with light soils. Such plants as spurry, corn mari- 
gold, sheep’s sorrel, and knawel appeared to be char- 
acteristic of sandy soils which are deficient in chalk; 
NO. 2305, VOL. 92] 
in other words, ‘‘sour” soils. Chalk provides a pecu- 
liar habitat for weeds, and the weed flora is very 
rich in species, some of which» are markedly char- 
acteristic. There is evidence now that a distinct 
association exists between the species of weed and 
the soil in which they grow. This association may 
be local, when the weed is symptomatic of the 
soil in one district, but not exclusively associated with 
it in another. On the other hand, it may be general, 
when a certain species is symptomatic or character- 
istic of the same type of soil in different districts. 
The nature of the crop also plays a part in determin- 
ing the weed flora. 
A note was presented by Miss Armitage on the two 
varieties of corn spurry. Spergula arvensis is a rather 
frequent weed on the red sandy loam in Hereford- 
shire, but the author never observed it in such develop- 
ment as to cause injury to crops. Spergula sativa, 
as she had seen it in Cheshire, is a terrible pest, 
causing marked injury both to roots and clover. It 
would be interesting to know whether this was always 
more harmful than S. arvensis. ; 
The section concluded with a very interesting and 
important paper by Sir Richard Paget on the pos- 
sibility of partnership between landlord and tenant. 
A form of agreement has been drawn up on this basis 
and was distributed at the meeting. An interestine 
discussion followed, which, however, is rather of 
general than of purely scientific interest. 
PSYCHOLOGY AT THE BRIETS Ea 
ASSOCIATION. 
SEPARATE Subsection of Psychology was 
formed this year at the British Association for 
the first time. The experiment was even more suc- 
cessful than had been anticipated. The general 
attendance was large and often crowded. Almost 
every experimental psychologist in Great Britain 
either attended the meetings or else sent or promised 
papers. The contributions received were so numerous 
that four meetings were held during afternoons. 
The proceedings of the subsection opened on Thurs- 
day with a series of papers, for the most part philo- 
sophical in character, The first paper was one by 
Dr. Wildon Carr, upon “The Absurdity of Psycho- 
physiological Parallelism even as a Hypothesis.’’ Dr. 
Carr suggested that in considering the relation be- 
tween body and mind, parallelism was not the only 
alternative to interaction; the relation might be 
solidarity of function, in which two independent 
realities are united. Mr. McDougall’s paper upon 
laughter aroused especial interest. Taking the chief 
theories of laughter hitherto propounded, he claimed 
that they did not account for all varieties of laughter, 
and, further, that they did not even seek to answer the 
most fundamental problem, namely to what end did 
the human species acquire this capacity for laughing ? 
The conditions exciting laughter he endeavoured to 
reduce to (1) situations that are mildly unpleasant, 
except so far as they are redeemed by laughter; (2) 
those things which would excite a feeble degree of 
sympathetic pain, if we did not actually laugh at 
them. The effects of laughter he described as con- 
sisting especially in an increase of the general and,. 
pleasurable sense of well-being. He added that 
the appearance of laughter seemed especially asso- 
ciated with the development of social life. From 
these considerations he argued that laughter proper 
(as distinguished from the smile, which in the adult 
has become secondarily associated with it) is a pro- 
tective reaction which shields us from the depressing 
influence of the shortcomings of our fellow-men. 
Laughter, in short, is the antidote to sympathy. 
