274 
THE monograph published by Prof. P. N. Ure, and 
issued by the Oxford University Press, on black glaze 
pottery from Rhitsona in Beeotia (pp. 63+xix plates, 
price 7s. 6d. net) is a useful contribution to our know- 
ledge of Greek ceramics. Our information on the 
history of the Boeotian federation from literary sources 
is confined to Thebes; that of the minor members 
must be discovered by the spade. If this pottery 
could be accurately dated it would supply much useful 
evidence. The present monograph has established the 
leading facts, which must be supplemented by further 
excavation and examination of the material. 
Tue Danysz rat virus, consisting of a cultivation 
of a microbe which produces a fatal infectious disease 
among rats, has been used with considerable success 
for the extermination of rats in many districts. The 
accompanying illustration shows the preparation of 
Saturating crushed oats with Danysz virus at Kaltern, Austrian Tyrol. 
the ‘‘ bait,” made by impregnating crushed oats with 
the virus, for use in Kaltern, a village in the Austrian 
Tyrol, which had suffered severely from an invasion 
of field rats. 
THE age of the earth has long been a favourite 
topic for discussion, and conclusions have been arrived 
at from time to time remarkable mainly for their 
variety. This variety is likely to characterise for a 
long time to come other conclusions that may follow, 
for the simple reason that at present we lack the data 
for dealing with the subject in a comprehensive way. 
Estimates of geologic time, founded upon one set of 
facts and assumptions, are found to be difficult to 
square with those based upon other and equally trust- 
worthy sets. Mr. H. S. Shelton considers some 
methods of attacking the problem in the October 
number of Science Progress. He points out the 
absence of sufficiently good data for the average rate 
of erosion of rocks, and suggests that further in- 
formation could be obtained if we possessed fuller 
details concerning the extent of particular local forma- 
tions. Of the geochemical methods he thinks the 
best is probably that based on calculations concerning 
the amount of limestone in the rocks of the earth; and 
from Mellard .Reade’s deductions he believes it is 
‘possible to assess a probable minimum of the order 
of 500,000,000 of years.’’ Respecting the estimates 
NO. 2296, VOL. 92] 
NATURE 
| by Dr. Hartman of one published by Engelenburg 
| in 1891, since which time the number of stations has 
[OcTOBER 30, 1913 
of Strutt, based on the study of helium and radio- 
active minerals, he says: ““The most we can now 
infer is a moderate minimum of time, a result that 
is given equally well by other data if properly 
handled.” Concerning biological evidence, he says: 
“The biologist has no independent standard of time. 
Vague as are the data of the geologist, those of the 
biologist are still more uncertain.’ Finally: “What 
we are entitled to say on the evidence before us— 
biological, geological, and physical—is this: It would 
be absurd to attempt, on very insufficient data, to 
give an estimate of the probable lapse of geologic 
time. But.there is, at the present day, no reason 
whatever why it should not be a thousand million 
of years or a time even greater.’ This does not carry 
us very far, and Mr. Shelton’s suggestions for further 
study of the problem are somewhat trite. 
Tue October number of The Entomologists’ Monthly — 
Magazine contains a memoir and portrait of the late 
Dr. O. M. Reuter, the celebrated hemipterist, who 
died on September 2, in his native town of Abo, at 
the age of sixty-three. 
Tue report of the Entomological Society of Ontario 
for 1912 mainly deals with the infestations of in- 
jurious insects in the Dominion and the best means 
of keeping them in check. Great aid in this work 
has been afforded by the establishment of field labora- 
tories in various districts, which have enabled investi- 
gations to be carried on over much wider areas than 
was previously possible. Another feature of the year’s 
work has been an increased importation of parasitic 
enemies of some of the most noxious insects, notably 
the introduction of cocoons of the larch-sawfly infected 
with an ichneumon-fly from the English Lake District. 
Tue beautiful colours of thin films observable with 
Mr. C. V. Boys’s scientific toy, ‘The Rainbow Cup,” 
were referred to in a Note in our issue of January 23 
of this year (vol. xc., p. 579). A cheap form of the 
instrument is now available from Messrs. J. J. Griffin 
and Sons, Ltd., the price being 2s. 6d. only instead 
of 25s. Though the new form is, of course, not so 
good as the more expensive instrument, it shows the — 
changing colour patterns in a very pleasing way, 7 
and should interest a large section of the general 
public. An explanatory pamphlet is included in the 
box containing the instrument and the soap solution. 
Tue Royal Meteorological Institute of the Nether- 
lands has issued a useful, paper on the rainfall of that 
country (Mededeelingen en Verhandelingen, 15), with — 
maps and tables showing the annual and seasonal 
distribution. The work is a continuation prepared 
greatly increased, and is the first instalment of a 
general climatology of the Netherlands. In addition © 
to the annual means for the whole period, which — 
differs for each station, all the means for the twenty- 
five years, 1881-1905, have been calculated, as this 
period has been adopted as a normal time for com- 
parison by the Solar Commission of the International 
Meteorological Committee. The extreme annual 
values for this series vary from 828 mm. (32°6 in.) 
