722 
a definite answer. An American observer, Dr. H. 
Skinner, has, indeed, committed himself to the state- 
ment that house-flies pass the winter only in the pupa- 
stage, but this is not in accord with the views of 
Messrs. Newstead and Jepson in this country. The 
point is of considerable importance in connection with 
the crusade against house-flies as disseminators of 
disease. 
To the Journal of the East Africa and Uganda 
Natural History Society for December, 1913,. Mr. R. B. 
Woosnam, Game Warden for British East Africa, 
communicates an important article on the relation of 
game animals to disease in Africa, with special refer- 
ence to the proposal to clear off such game animals 
in certain parts of East Africa witha view of stamping 
out tsetse-fly disease and other maladies. The theory 
hitherto largely favoured by experts is that game 
animals alone serve as ‘‘reservoirs” for the trypano- 
somes, and other blood-parasites, by which such 
diseases are caused; but the author points out that not 
only is there a strong probability, but likewise a prac- 
tical certainty, that other animals serve in a similar 
capacity. And this being so, the futility of attempt- 
ing to kill off all the game animals in certain districts 
is self-apparent. In the opinion of the author, a far 
more hopeful plan is to rely on the possibility of pro- 
ducing or accelerating immunity to the diseases in 
question in the animals liable to be infected. “If,” 
writes Mr. Woosnam, ‘wild animals can acquire an 
immunity in nature and domestic native cattle can 
also acquire immunity [which in certain instances 
they undoubtedly do], is it mot possible that the 
greatest success may eventually result from an arti- 
ficially produced immunity?” 
In a valuable report on the effect of water on the 
cultivation of cotton (Egyptian Ministry of Finance 
Survey Department, Paper No. 31, 1913), Messrs. 
Hughes and Hurst, who were assisted in their field 
work by Messrs. Bolland and Ferrar, give details 
of a series of experiments made with a view of 
eliminating other factors in an estimate of the influ- 
ence upon the cotton yield of the level of saturation in 
the soil. Their general conclusion is that with the 
subsoil water at a low level fairly heavy watering gives 
greater yields than very light watering, which may 
easily be pushed so far as seriously to affect the yield. 
They find, however, that fairly heavy watering delays 
the ripening of the crop, and they point out that too 
wide an interpretation is not to be placed on the results 
obtained from the experiments, the chief importance 
of which lies in the methods adopted, especially the 
arrangement of the experimental plots in such a 
manner as approximately to eliminate the effect of 
factors which varied from point to point of the fields. 
Ir would appear, from investigations by Mr. W. R. 
Dunlop (West Indian Bulletin, vol. xiii., No. 4), that 
certain groups of varieties of sugar-canes possess differ- 
entiating characteristics as regards their stomata, and 
that if the general morphological and anatomical char- 
acters of_the varieties be taken into consideration, each 
one variety can be identified by its leaf alone. The 
stomatal density per unit of area is one of the chief 
NO. 2313, VOL. 92] 
NATURE 
[FEBRUARY 26, I914 
characteristics, though in the investigation under re- 
view the range of variation has not been determined 
with sufficient accuracy to permit more than the classi- 
fication of the varieties exathined into groups as — 
regards stomatal densities. The relation of the ratio 
of the total stomatal area to the entire surface of the 
leaf, and the susceptibility of any variety to drought 
is discussed, and actual observation has shown that a 
variety possessing a high stomatal area with other 
hydrophyllous characters appears to be unsuited for 
cultivation in areas of low rainfall and humidity. 
Whether any general relation exists between sucrose 
content of varieties and stomatal characteristics has 
yet to be determined, but such observations would — 
appear to provide a useful guide in future selection 
of sugar-cane for drought resistance. 
One of the useful articles in the recently published 
Journal of the Scottish Meteorological Society (vol. xvi) 
is a somewhat laborious ‘investigation of ‘‘A Possible 
Two-hourly Period in the Diurnal Variation of the 
Barometer,” by Mr. M. M’Callum Fairgrieve. The 
paper was suggested by certain departures from a 
smooth curve every alternate hour, shown by the result 
given by Dr. Chree in a paper on the barometric 
pressure at Castle O’er (Quart. Journ. Roy. Met. Soc., 
October, 1911). Mr. Fairgrieve examined long series 
of observations at some of the Meteorological Office 
observatories, and other places, and found that a two- 
hourly oscillation was very apparent at certain places, 
while at others there was little indication of any such 
variation. The author finds it difficult to assign a proper 
explanation of the results obtained, whether physical 
or instrumental, but suggests that it is obviously of 
importance that the point should be cleared up. 
Ir is well known that while the number of regular 
solids is limited, a similar limitation extends to 
“polytopes '’ in multi-dimensional space, the cube, regu- 
lar tetrahedron and octahedron being the only types 
which can be extended indefinitely to the higher dimen- 
sions. There are, however, certain semi-regular poly- 
hedra which play an important part in crystallography. 
We have now received papers from Dr. P. H. Schoute, 
reprinted from the transactions of the Cambridge 
Mathematical Congress, and Dr, E. L. Elte (Amster- 
dam Proceedings, 1912), dealing with the different 
degrees of regularity and characteristics of the various 
semi-regular polytopes in multi-dimensional space. 
While these interesting problems are being com- 
petently treated by mathematicians, the popular fallacy 
of ‘the fourth" dimension seems as hard to eradicate 
as ever. Prof. Samuel M. Barton’s article in The 
Popular Science Monthly for October is correct 
enough in its geometrical facts, but the use of the 
word ‘‘fourth,’’ for the more correct terms, ‘ four" 
and ‘“‘many,’’ will be likely to militate against the 
usefulness that would accrue from an essay dealing 
professedly with ‘* hyperspaces.”’ 
AFTER conference with the American incandescent — 
lamp manufacturers, the United States Bureau of 
Standards has issued a sixth edition of its circular 
containing standard specifications for such lamps. 
Although the specifications were originally intended for 
