114 
Tue ‘“Terrapin”’ scale (Eulecanium nigrofasciatum) 
is the subject of Bulletin No. 351 of the U.S. Dept. 
of Agriculture, written by Mr. F. L. Simanton. This 
is a. North American ‘insect, closely: allied to® our: 
European E, persicae, destructive to peach and plum, 
and feeding also on thirty other trees and shrubs. The 
females hibernate on the twigs, where, instead of laying 
eggs, they give birth to active young, which migrate 
to the leaves. Much damage is caused by the insects’ 
honeydew secretion, which disfigures the fruit. The 
bulletin is well illustrated, and contains directions for 
remedial treatment, early spraying with a linseed oil 
and gasolene emulsion being especially recommended. 
Notes of much interest appear in the Zoologist for 
September on the mammalian fauna of North Car- 
diganshire. The author, Mr. Frank Wright, records 
the occurrence, during the last ten or twelve years, of 
a number of polecats of a very light colour, some 
individuals, furthermore, exceeding in size the more 
normally coloured animal. Both light- and dark- 
coloured individuals Kave been taken from the same 
pest. The pine-marten, he remarks, is now exceedingly 
rare, but a few apparently survive on the high plateau 
east of Tregaron. The foxes of the uplands also seem 
to differ from the type in the matter of coloration, 
being much greyer. But a specimen taken near the 
summit of Plinlimmon was quite black instead of white 
on the under parts. 
Mr. Zonia Baber, in the Scientific Monthly for Sep- 
tember, raises a timely protest against the wholesale 
slaughter of whales which is at present taking place 
throughout the seas of the world, and this without 
the slightest attempt at preventive legislation. The 
author, in his essay, ‘The Oceans: Our Future Pas- 
tures,” holds that the time will come when men will 
have to depend upon the larger Cetacea for their meat 
supply, since the grazing of cattle will be impossible 
owing to the density of the population, which will cover 
the whole habitable globe. While we by no means 
agree with this view, we are at one with him that, 
for other and scarcely less cogent reasons, the present 
ruthless and wasteful exploitation of our whale 
fisheries constitutes a deplorable lack of foresight on 
the part of those engaged therein. The matter de- 
manded international legislation long ago, and even 
now it is not too late, though, unless it come speedily, 
the Greenland and humped-back whales and the grey 
whale (Rhachi anectes) will have taken their places 
with Steller’s sea-cow and the great auk—victims to 
man’s greed, 
Ir is clear from the annual report of the British 
Museum (1915) that the Natural History Departments 
have been able to render useful aid to the military 
authorities in matters directly bearing on the war. 
In one case a leech, removed from the nose of a 
soldier invalided home from the Dardanelles, was sent 
to the museum from the military hospital in order 
that it might be identified and its habits described. 
A report on the matter was prepared by the keeper of 
the Zoological Department embodying useful advice 
and instructions, and this report was sent to 
the medical officers serving in the Mediter- 
ranean in order that .the necessary precautions 
to avoid further infection might be taken. The 
Botanical Department was enabled to furnish the 
authorities of the Naval Air Service with valuable 
» information in regard to wood suitable for airship con- 
struction. Further assistance was also given in regard 
to a fungus which was attacking the fabric of airships. 
Valuable work has also been done in regard to the 
supposed hibernation of the house-fly, and to the whal- 
ing industry in the Antarctic seas, which is carried on 
NO. 2450, VOL. 98] 
NATURE 
[OcTOBER 12, 1916 | 
in the neighbourhood of South Georgia so thoroughly 
that some species are threatened with extinction. 
Tue best-known instances .of luminosity in. insects 
are to be found among the beetles; the various species” 
of glow-worm and firefly belong to this order. But 
the same, or an analogous, phenomenon is occasionally’ 
observable in other insect groups, as, for example, in 
the ‘fungus gnats” and crickets. There are at least 
two well-authenticated records of luminosity in the 
larve of moths, and quite recently the Rev. J. Hol- 
royde, vicar of Patcham, has reported to us an observa- 
tion of luminous larve near Brighton. The species of 
these larvae was not determined, but they appear to” 
have been the caterpillars of a moth, probably a Noc- 
tuid. Boisduval, whose record is one of those above 
alluded to, believed that the luminescence in his larvae. 
was due to disease, and it has been suggested that 
decomposition due to bacterial infection is the cause 
of a similar appearance that has been described in 
other insects not usually luminous, as Chironomus (a 
kind of gnat) and the so-called “lantern flies” of 
South America. It is evident that the exceptional’ 
production of light in the cases just mentioned is very 
different in nature from the entirely normal illumina=- 
tion of the glow-worms and fireflies, though it may 
equally be due to the oxidation of some organic 
material. 7 
Tue excellent work in agricultural science which is 
being carried on at Moscow under the guidance of 
Prof. D. N. Prianichnikow is amply illustrated in the 
recently issued report (vol. x.) of the Agronomical 
Laboratory for the year 1914. As in past years, much © 
attention has been devoted to the investigation 
of the merits as fertilisers of various natural phos- 
phates and potash-bearing minerals, fully one-half of 
the papers included in the report having reference to 
these products. The assimilation and utilisation of 
ammonia by the plant have also received considerable 
attention. The experiments with phosphates have 
demonstrated the relatively high value of certain of the 
Russian phosphorite deposits, increases of crop as high 
as 60 to 7o per cent. of the highest obtained with 
superphosphate having been recorded in tests with 
cereal crops. This is in marked contrast to the results 
of earlier experiments recorded in previous reports, 
which indicated that, in general, phosphorites are 
almost valueless for cereal crops, though of appre- 
ciable value for leguminous crops, 
UseFut data as to the limits of tolerance of crop 
plants for sodium salts present in the soil are given 
by Messrs. Headley, Curtis, and Scofield in the latest 
issue of the Journal of Agricultural Research (vol. vi., 
p. 857). Experiments in Nevada have shown that 
the limit of tolerance is extremely variable, being in- 
fluenced not only’ by such factors as kind of soil, 
salt, or crop, but the same crop plant shows marked 
differences in tolerance at different periods of its 
growth. So far as the amount of salt is concerned 
the limit of tolerance is dependent not so much upon 
the total quantity of the salt that may be present in 
the soil as upon the quantity that exists in the soil 
solution, and is recoverable from the soil by means of 
extraction with water. In pot experiments with soil 
from a tract of salt land in Nevada it was found 
that the proportion of recoverable salt which would 
reduce by one-half the growth of wheat seedlings was 
for sodium carbonate or bicarbonate 0:04 per cent. 
of the dry weight of the soil, for sodium chloride 
0-16 per cent., and for sodium sulphate 0-35 per cent. 
The proportion of recoverable salt which prevented 
germination of wheat was for the carbonates 0-13 per 
cent., for the chloride o52 per cent., and for the 
sulphate 0-56 per cent. 
