APRIL 29, 1915] 

Tue Ichthyological Laboratory of Astralkhan ascer- 
tained the existence of more than sixty representatives 
of the Caspian fauna in the branches of the lower 
Volga, some species of Mysidze occurring at a distance 
of 180 miles from the sea. A dozen years ago also a 
number of Caspian forms were found near Saratof 
by the biological station at that town, and the same 
forms were found in 1911 by A. Derzhanin in the 
Volga below Kazan and in the lower Kama, one of 
which, Metamysis strauchi, occurs as far up as Yaros- 
lavl. This is identical with the M. volgensis of Tret- 
yakof, to which he assigned an Arctic origin. These 
Caspian forms Mr. Derzhanin believes to have been 
left behind on the regression of the Maeotis-Caspian 
sea (Proceedings of the Naturalists’ Society of the 
University of Kazan, 1912-13). 
Tue Journal of the Department of Agriculture and 
Technical Instruction for Ireland (No. 2) contains 
several papers of general interest. Mr. Falkner C. 
Mason describes a series of experiments which have 
been carried out during the past year in the veterinary 
hygiene division of the Department to ascertain how 
long an injection of tuberculin will confer upon a 
tuberculous animal the power of resistance to a second 
injection. This fact has occasionally been taken ad- 
vantage of by unprincipled persons for fraudulent pur- 
poses. In the paper now referred to the trustworthi- 
ness of the test in such circumstances has been studied 
and methods are suggested to counteract any attempt 
to render the test abortive. The ‘Boom in Flax”’ is 
dealt with by Mr. A. L. Clark, who gives statistics of 
- the extraordinary advance in the prices of this crop 
brought about by the war. All past records have 
been broken; not even during the American Civil 
War has flax realised so high a price as it is being 
sold at to-day. Mr. Hunter deals with the question 
of the improvement of the flax crop by propagation 
from selected plants, a field of work which apparently 
offers a very hopeful outlook. 
Tue history of the plantation rubber industry of the 
east is given by Mr. T. Petch in the recently issued 
part of the Annals of the Royal Botanic Gardens, 
Peradeniya (No. vii. of vol. v.). The story affects 
Ceylon principally, where the records have on the 
whole been carefully kept. It is unfortunate that 
certain gaps in the early history are due to the lack 
of proper records during Thwaite’s directorship. The 
successful introduction of Hevea is due to Wickham, 
and possibly also to Cross, through the agency of 
Kew; a few plants have probably also been derived 
from those collected by Collins near Para. Much 
diversity, both in leaf and bark characters, is notice- 
able among the trees of the plantations, but there 
appears to be no ground for supposing that the trees 
in the east differ essentially from those in Brazil from 
which fine hard Para rubber is obtained. The reports 
of Wickham and Cross are reprinted, and careful 
details are given of the distribution of the original 
trees in and from Ceylon. An account of the planta- 
fions in the east generally is also given, and js 
followed by chapters on tapping experiments, Brazilian 
methods, ete. The history of the introduction of 
NO. 2374, VOL. 95] 
NATURE 

2939 

Ceara and Castilloa in 1876 and of other rubber- 
yielding plants is also given. 
Tue Geological Survey of Canada has published as 
Memoir No. 38, in three cloth-bound volumes, the 
report of the Chief Astronomer on the North American 
Cordillera, forty-ninth parallel. The author of this 
work, Prof. R. D. Daly, acted as geologist to the 
International Boundary Commission between 1901 and 
1906, and the report, circulated in 1915, bears the date 
Ig12 upon its title-pages. The recording of the field- 
observations in a highly mountainous region was 
hampered by the absence of large-scale and accurate 
maps; but coloured geological maps and sections are 
here published of the whole traverse across British 
Columbia, from long. 114° W. almost to the coast. 
Fossiliferous horizons are unfortunately scarce; but 
the igneous phenomena provided ample material for so 
keen a worker as Prof. Daly, and have led him to 
insert as chapter xxiv. an “introduction to the theory 
of igneous rocks.’"’ The possible origin of pre-Cam- 
brian dolomites and limestones by chemical precipita- 
tion is discussed with similar breadth of view in 
chapter xxiii. During hard mountaineering work, 
the author’s mind always sought for explanations, and 
this adds considerable brightness to his description 
of the structure of the Rocky Mountains, the Sel- 
kirks, and the Cascade Range. An overthrust of 
forty miles is suggested as one explanation of the 
grouping of strata in the Clarke Range. 
AmMonG recent Bulletins of the Commission Géo- 
logique de Finlande, H. Hausen issues (No. 31) a 
study of types of porphyry found in the glacial beds 
of south-west Finland, and points out that many of 
these are still of uncertain origin and cannot be used 
as guides in estimating directions of ice-movement. 
In No. 32, he utilises well-recognised types of erratics 
in tracing the spread of glaciers from Fennoscandia 
into Russia, and shows how the ‘ Baltic ice,’ moving 
mainly from north to south, has locally obscured the 
traces of the earlier and greater glaciation of Russia 
by ice from the north-west. One of his maps shows 
interesting features of drumlins near Dorpat, and a 
lake at the south end of the Gulf of Riga, held up 
between the ice-front and an abandoned terminal 
moraine. W. W. Wilkman (No. 33) deals with the 
later shore-lines in eastern Finland, and indicates 
wave-like movements of the ground; while the direc- 
tor, J. J. Sederholm, in No. 37, emphasises the influ- 
ence of fracture-lines in controlling existing features 
in Fennoscandia. He urges that fracturing and fault- 
ing may characterise the cover which conceals folded 
masses, and that this zone is commonly removed from 
considerable mountain-chains. Students of igneous 
contacts and metamorphism will find much to interest 
them in P. Eskola’s detailed memoir (No. 4o), written 
in English, on the Orijarvi region. The alterations 
undergone by limestones, siliceous ‘‘leptites,’ and 
basic igneous rocks consist almost uniformly in the 
introduction of iron and magnesium and the leaching 
out of lime and alkalies. 
Tue Canadian Department of Mines continues the 
issue of its useful publications with the object of 
