sate 
[Marcu 3, 1923 




302 NATURE 
Research Items. 
PsycHoLoGy IN ENGINEERING.—In his Sidney 
Ball memorial lecture (Scientific Management and 
the Engineering Situation, Barnett House Papers, 
No. 7, Oxford University Press, 1922. Price 1s.), 
Sir William Ashley discusses the much debated 
problem of scientific management, with special 
reference to the engineering trade. He reviews its 
beginning in America, its development there, and the 
interest aroused in it in this country. He points out 
that, as it has arisen in the engineering trade, it 
bears the marks of people accustomed to think in 
terms of the exactly measurable, engineering being 
largely a matter of exact formule. Unfortunately 
for the mechanist, the human being is quite frequently 
influenced by motives which defy exact measurement. 
Aiming a# increasing output and thereby diminishing 
the cost for each unit of work, it was attempted by 
time and motion study and a bonus system to settle 
the problem of wages. It has, however, introduced 
more complications to an already complicated 
problem, and just where it leaves the domain of 
mechanics to enter that of psychology, it breaks 
down. English psychologists criticise the so-called 
scientific management, not because it calls itself 
scientific, but because it is not sufficiently scientific. 
The application of science to industry is valuable, 
but it is not scientific to apply the principles of 
one science to problems belonging to another of a 
quite different order. 
FLEAS AND PLAGUE IN INDIA.—One of the most 
striking features of the prevalence of plague in India is 
the relative immunity of Madras compared with, for 
example, Bombay or the Punjab, The Advisory Com- 
mittee for Plague Investigation examined the prob- 
lem at length, but failed to find any satisfactory 
explanation. It was believed at that time that the 
prevalent rat flea all over India was Xenopsylla 
cheopis. Rothschild, however, afterwards found that 
under that identification three very closely allied 
species—X. cheopis, X. astia, and X. brasiliensis— 
had been confused, and Hirst pointed out that the 
distribution of plague in India and Ceylon corre- 
sponded well with the hypothesis that the real X. 
cheopis was alone an effective transmitter of the 
disease. 
Research, vol. x., 1923, p. 789) a full series of experi- 
ments confirming his earlier work, and showing that 
X. astia, the prevalent rat flea in Madras, will carry 
plague from one animal to another only with much 
more difficulty than X. cheopis, the rat flea of Bombay. 
Details of plague epidemics in Colombo, where plague 
has never become widely spread and where the fleas 
are mostly X. astia, with a few X. cheopis, bear out 
his thesis in a striking manner. It seems as if a 
considerable advance has been made in the epidemi- 
ology of plague which illustrates the fundamental 
importance of systematic zoology in these problems. 
EFFECTS OF THE CONTIGUITY OF ORGANISMS.—In a 
series of experiments on the influence of density of 
population on longevity in the fly Drosophila, R. Pearl 
and S. L. Parker show (American Journal of Hygiene, 
vol. ili., 1923, p. 94) that the optimal density for dura- 
tion of life is not the minimal density The mean 
duration of life increases with increase of density of 
population up to a certain point, and afterwards, as 
would be expected, declines. Thus, starting with about 
2 flies per ounce bottle the average life is 28 days, 
which increases rather rapidly to about 40 days with 
50 flies per bottle, declines again to 28 with a density 
of about 90, and to 17 and 13 with densities of 150 
NO. 2783, VOL. 111] 
He now reports (Indian Journal of Medical : 


and 200, This favouring effect of organisms on one q 
another recalls the observations of T. B. Robertson _ 
(Biochemical Journal, vol. xv., 1921, p. 612), who 
found that the rate of asexual multiplication of the 
infusorian Enchelys was much greater if the culture 
contained two individuals to start with than if only — 
one was present. It is too familiar to most bacteri- — 
ologists that the dispersion of a few bacteria in a 
large volume of culture liquid will often fail to give — 
a successful growth which is obtained with ae 
if the same number of organisms is sown in a small — 
quantity of medium. All this suggests a general 
proposition that contiguity to like individuals is, 
up to a certain point, favourable to the life of 
organisms. 
Cork Formation.—In a continuation of the useful 
physiological studies in plant anatomy carried out | 
at the University of Leeds, Prof. J. H. Priestley and | 
Miss L. M. Woffenden (New Phytol., vol. 21, No. 5) * : 
have made a study of the causal factors in cork — 
formation. A causal sequence can be traced both 
in the formation of wound cork and leaf scars, as well 
as in the natural internal origin of a cork layer. A 
parenchyma surface is first blocked by suberin 
deposits in presence of air. This is followed by the 
accumulation of sap at the blocked surface, and this _ 
in turn gives rise to the development of a phellogen _ 
or cork cambium in the area involved. In the ~ 
absence of air, a meristematic zone may be artificially 
produced without the formation of cork in the cell 
walls. 

GROWTH AND MATURATION OF THE SUGAR CANE,— 
Dr. Kuyper has described the physiology of sugar : 
formation, and the methods used in Java to harvest 
the canefields at the exact moment of highest | 
maturity in ‘The Formation of Sugar and the 
Ripening in Sugar Cane” (Suikervorming en ryping 
by het suikerriet), Archief voor de Suiker-industrie 
in Nederlandsch Indié, 1922, 2e deel blz. 195-321, 
Mededeelingen No. 5. Cultivation is so directed that 
the fullest use is made of the available light, and in | 
this connexion the author discusses the questions ~_ 
of the optimum distance between the plants and rows, 
the effect of tying up the canes as a preventive 
against lodging, the influence of yellow stripe disease 
upon sugar production, and the relation between 
cellulose formation and sugar content. In Java 
the process of ripening of sugar cane is carefully 
watched by means of analyses of samples taken 
regularly every two or three weeks. The course of — 
maturity can be judged by the relation between total — 
solids and the quotient of purity (Brix and RQ) in | 
the different parts of the stalk; the glucose ratio 
changes in a way which is the reverse of that seen 
in the percentage of available sugar. It has been 
proved that the time of planting and the age of the 
cane have much influence upon the maturation 
process, as if climatic conditions are favourable 
the sugar content of fields of different ages may 
reach almost the same final percentage, whereas 
under unfavourable conditions the late planted canes 
will not be so rich in sugar. Maturing is found to 
progress most regularly in places in which the rainfall ] 
is very low during the milling season, but where the 
soil contains sufficient moisture to prevent the cane ~ 
from dying without permitting further growth to ~ 
occur, 
OCEANOGRAPHY OF THE SOUTHERN OCEAN.—A note 
by Commander F. A. Worsley in the Geographical 
