142 
NATURE 
[OcToBER 2, 1913 
tion in vol. ii. of the Science Bulletin of the Institute, 
the first portion of this dealing with the bats, and the 
second with two species of molluscs. 
In the September number of The American 
Naturalist, Prof. H. H. Newman, of Chicago Uni- 
versity, discusses at length the remarkable pheno- 
menon of polyembryonic development exhibited by 
Dasypus novemcinctus and certain other species of 
armadillos, and its bearing on sex-determination. 
The females of these species, when pregnant, invari- 
ably develop four embryos, enclosed in a single 
chorionic envelope, which are always of the same 
sex, the process of development being summarised by 
the author as follows :—‘‘ The ovogenesis is normal; a 
single egg is fertilised by a single spermatozoon; the 
cleavage is apparently normal, and gives rise to a 
blastodermic vesicle similar to that of other mammals, 
especially the rodents; germ-layer-inversion affords an 
easy mechanism for producing several embryos in a 
single chorion, for the quadruplets arise by means of 
dichotomous budding of the inner ectodermic vesicle 
without affecting the enveloping membranes of the 
vesicle, which form the common chorion; the sub- 
sequent embryonic development of the several embryos 
is as independent as it can be under monochorial 
conditions, since each individual has its own separate 
amnion, allantois, umbilicus, and placenta.” 
M. Fujioka contributes an elaborate study of the 
structure of the wood in the Japanese conifers to the 
Journal of the College of Agriculture, University of 
Tokyo, vol. iv., No. 4. The detailed descriptions of 
the wood in the various species examined are followed 
by a key to the Japanese genera of Conifere based 
upon the history of their wood, and the memoir is 
illustrated by seven plates containing eighty-four very 
fine photomicrographs. 
WE have received a copy of the Proceedings and 
Transactions of the Croydon Natural History and 
Scientific Society, 1912-13, which contains various 
items of interest. Among these there is an account 
of the organisation of the Regional Survey of Croy- 
don, which the society have undertaken, and which, 
when completed, will form one of the most elaborate 
records of the natural history of a limited area that 
has been made. The volume also includes reports of 
addresses given by Dr. H. F. Parsons and Mr. A. G. 
Tansley, dealing respectively with ‘‘ Plant Growth and 
Soil Conditions” and with “‘ Practical Study of Vege- 
tation in the Field.” There is an extensive appendix 
containing the records of the Meteorological Com- 
mittee, and giving the daily rainfall throughout the 
year 1912 at various stations in the district. 
Miss M. C. KNOWLES, in a paper on the maritime 
and marine lichens of Howth (Sci. Proc. Royal Dublin 
Soc., August, 1913), gives an interesting account of 
the lichen vegetation of Howth Head, Dublin Bay, 
illustrated by several beautiful photographs by Mr. 
R. Welch. More than half of the memoir is occupied 
by a detailed description of the ecology of the lichens 
which inhabit the siliceous rocks on the coast and 
form more or less sharply defined belts or zones 
dominated, from above downwards, by species of 
NO. 2292, VOL. 92| 
Ramalina, orange-coloured lichens, species of Lichina, 
Verrucaria maura, and marine Verrucarias. Three 
new species are described, and notes are given on 
some remarkable forms of ,Ramalina, while the 
memoir as a whole may be regarded as the most 
important contribution that has yet been made to the 
ecology of the littoral lichen vegetation of this country. 
WE have received a Spanish edition of the “‘ Inter- 
national Codex of Resolutions adopted at Congresses, 
Conferences, and at Meetings of the Permanent Com- 
mittee, 1872-1910," translated by the Central Observa- 
tory of Manila from the second German edition. The 
preparation of this useful work was recommended by 
the International Meteorological Committee at the 
meeting at Southport in 1903, and Drs. Hellmann and 
Hildebrandsson were requested to undertake it. At 
the conference at Innsbruck, in 1905, a manuscript 
copy of the Codex was presented, and its publication 
in English, French, and German was urged as “a 
most valuable means for promoting international 
meteorological work.’’ In view of the extended use 
of Spanish in central and southern America, and also 
in eastern Asia, Sefor J. Algué was thanked for his 
offer to arrange for its publication in that language. 
It should be mentioned that due reference was made 
by Dr. Hellmann to a somewhat similar work pub- 
lished by Dr. Wild (then president of the International 
Meteorological Committee) in the Repertorium fiir 
Meteorologie, vol. xvi., which contained particulars 
for 1872-1891, and was at the time of considerable 
value. 
In a well-known experiment of De la Rive’s, one 
end of an electromagnet projects into an evacuated 
bulb containing two electrodes, one of which takes 
the form of a ring. When a discharge is passed the 
luminous column is seen to rotate round the magnet 
pole. This experiment receives various interesting 
extensions in a paper by Prof. Righi on “ Rotazioni 
Ionomagnetiche (R. Accad. di Bologna, February, 
1913). In a typical experiment the two electrodes, 
which are here cylindrical, are placed in the same 
vertical line, and the lower one is surrounded by a 
suspended metal cylinder. An external magnet pro- 
duces a field parallel to the line joining the elec- 
trodes. When the discharge passes it is found that 
the cylinder rotates. The theory shows that the effect 
is due to the oblique impact, on the cylindrical walls, 
of the ions carrying the discharge. 
WE have received a copy of Dr. P. W. Bridgman’s 
paper on the thermodynamic properties of twelve liquids 
between 20° C. and 80° C. and up to 12,000 kilo- 
grams per sq. cm. The work was carried out at the 
Jefferson Physical Laboratory of Harvard University 
by the aid of the Rumford Fund. The liquids used 
were methyl, ethyl, propyl, isobutyl, and amyl 
alcohols, ethyl ether, acetone, carbon bisulphide, 
phosphorus trichloride, and ethyl bromide, all of which 
were obtained in an approximately pure state. The 
liquid was contained in a cylinder closed by a piston, 
the motion of which determined the change of volume. 
The pressure applied was measured by the change of 
electrical resistance of a standardised manganine wire. 
