564 
in the intestine of the common leather-jacket, or 
larval crane-fly. It appears that no fewer than eight 
kinds of flagellates and two amcebe are found in this 
situation, feeding upon a rich bacterial flora. The 
author suggests that the term ‘“parasite’’ is scarcely 
applicable to such organisms, which appear to fulfil 
a useful function in keeping down the bacteria, and 
points out that the richest intestinal fauna was gener- 
ally found in the largest and healthiest looking grubs. 
She believes that totally different species of animals, 
when they frequent the same feeding grounds, may 
serve as hosts to the same species of protozoan para- 
sites. The beautiful form known as Rhizomastix 
gracilis was described by Alexeieff in 1912 from the 
Axolotl, and Miss Mackinnon now records and figures 
it from the crane-fly larva, filling in certain particulars 
as to its life-cycle. A new subgenus and species, 
Tetratrichomastix parisii, is proposed for another 
flagellate from the same host, the subgeneric name 
being chosen on analogy with Tetratrichomonas. It 
is true that Tetratrichomonas possesses an undulating 
membrane which may represent a fifth flagellum, but 
the fact that five separate flagella are actually present 
in the new subgenus makes the proposed name dis- 
tinctly misleading. 
Tue rust-fungi (Uredinez) of Nova Scotia are dealt 
with in detail by W. P. Fraser in vol. xii., part 4, 
of the Proceedings of the Nova Scotian Institute of 
Science. The author gives an excellent introductory 
account of the structure and life-history of the group, 
followed by detailed descriptions of the ninety-two 
species known from Nova Scotia, including several 
not hitherto found in any other part of North America. 
In the descriptions the terminology proposed by 
Arthur in his well-known work on North American 
Uredinez is followed, though it is doubtful whether 
botanists in general will perceive any special advan- 
tage in the new terms adopted for the various pore- 
forms in place of those which have become familiar 
by long usage. 
A VALUABLE contribution to our knowledge of soil 
gases and the complex conditions surrounding the 
growth of crops in swamp rice soils has been made 
in the Memoirs of the Department of Agriculture in 
India, vol. iii., No. 3, chemical series, by Mr. W. H. 
Harrison and Subramania Aiyer. The results obtained 
show that the normal fermentation of green manure 
in swamp paddy soils leads to the production of a 
relatively large quantity of methane, a smaller amount 
of nitrogen, together with some carbon dioxide and 
hydrogen. This in itself is not surprising when one 
considers the anaerobic conditions obtaining in the 
flooded soil, but it has been further observed that the 
introduction of a crop greatly modifies the composition 
of the soil gases, either by directly retarding the rate 
of fermentation and restricting the formation of 
methane and hydrogen, or by a portion of the inter- 
mediate products of decomposition being removed out 
of action by absorption by the roots. The latter has 
been experimentally demonstrated in various recent 
investigations, and the nutrition of paddy rice would 
appear to consist in the assimilation of nitrogen either 
in the form of ammonia or of organic compounds pro- | 
NO. 2307, VOL. 92| 
NATURE 
[JANUARY 15, I9I14 
duced by the decomposition of the proteids of the 
green manure, since nitrification is impossible under — 
the anaerobic conditions that obtain in these soils. 
TuoseE who desire to keep pace with modern views 
on  crust-displacements and mountain-structure, 
whether as an aid to geographical or geological 
studies, will find a well-illustrated summary in Otto 
Wilckens’s ‘‘Grundziige der tektonischen Geologie” 
(Jena: G. Fischer; price 3.50 marks), which covers 
matters that are not to be found in every text-book. 
Tue Government Printing Office at Kingston, 
Jamaica, has issued a coloured geological map of 
Jamaica, which may be found generally useful, on 
the scale of one inch to twenty miles. It is published 
separately as Publication No. 420, with an explanation 
by Maxwell Hall, but might be overlooked by geo- 
logists, since it officially forms part of the memoir on 
“The Rainfall of Jamaica from about 1870 to end 
of 1909.”’ 
Tue Cotteswold Naturalists’ Field Club maintains 
its reputation for original publication in its eighteenth 
volume (1913). L. Richardson and C. Upton deseribe 
new species of brachiopods from the Inferior Oolite, 
and the former author, with E. T. Paris, publishes 
a supplement to previous work on the echinoids from 
the same formation. The photographs of important 
species are in both cases admirable. The country 
where William Smith found such welcoming friends 
as Benjamin Richardson and Joseph Townsend will 
never forget the principles of stratigraphical geology. 
“A BrsriocrapHy of Russian Ethnographical 
Literature’ forms vol. xl., No. 1, of the Zapiski of 
the ethnographical section of the Russian Geograph- 
ical Society. It covers the years 1700 to 1910, and is 
compiled by M. D. K. Zelenin on behalf of the Com- 
mission for the Construction of an Ethnographical 
Map of Russia. 
Pror. Kuznersor, whose historical sketch of the 
flora of Daghestan has already been referred. to in 
these pages (vol. Ixxxvili., p. 600), gives an account 
of his investigations and results in the Izvestiya of the 
Russian Geographical Society, Nos. i.-iii., 1913. At 
the end of the number is a map showing the distri- 
bution of the most distinctive forms, and a full list, 
compiled by M. P. P. Popof, of the plants collected. 
Tue narrative of M. Zhitkof, who explored the 
Yamal Peninsuia, in 1908, is published in the Zapiski 
of the Russian Geographical Society, vol. xlix. The 
name Yamal, meaning “end of the earth,” in_the 
Samoyed language, is more correct than the usual 
Yalmal, which signifies ‘‘mouth of the river’? (Ob). 
The country is low, especially in the north, where 
it slopes down to the Malygin strait, and the water- 
shed is there inconspicuous. In the south it is more 
marked, rising at the Yarro-to lakes to 300 ft. above 
sea-level. The eastern and western coasts often rise 
in steep cliffs of clay and sand. Lakes and basins 
partially filled up are numerous in the central part. 
The work includes chapters on the fauna and flora, 
the Samoyeds and reindeer grazing. M. Rudovits 
contributes a report on the meteorological observa- 
a 
