454 
tion of the address is devoted to a brief survey of 
the cereal rust fungi, a subject to which Mr. . Pole 
Evans has contributed much valuable work in the 
Transvaal. Wheat, oats, rye, and barley are all 
attacked by the black rust, Puccinia, graminis,. Pers., 
and the first three cereals are also each attacked by a 
second rust fungus. Maize is also subject to two 
rusts, P. maydis, Bereng., and P. sorghi, Schw. It 
will be remembered that Mr. Pole Evans discovered 
that Oxalis corniculata is the alternative’ host of P. 
maydis in South Africa. For the other Puccinias no 
alternative host is yet known, and there are no bar- 
berry bushes in the country. P. graminis therefore 
exists without its zcidial host, and as the over-winter- 
ing of the uredo, or spring spores, does not appear to 
be entirely responsible for the sudden outbreaks of 
disease, the history of the telentospores in South Africa 
is an important problem deserving of careful research. 
Tue Archivos do Jardim botanico do Rio de Janeiro, 
vol. i., fac. i., which has recently reached us, contains 
an account of new or little-known Amazonian plants 
by A. Ducke, illustrated by nineteen plates. ~ The 
volume also contains a well-illustrated account of the 
remarkable genus of Cactacez, Rhipsalis, by A. Léf- 
gren. Among the new plants figured by Ducke are 
two new species of the Cycadean genus Zamia; 
one, Z. Lecointei, was found near Obidos, and 
is the first Cycad to be found in the province of 
Para. Another, from the south-east of Colombia, may 
be the same species as that found by Spruce many 
years ago,in Uaupes. Ducke concludes his paper with 
descriptions and notes of species of the Solonaceous 
genera Ectozoma and Marckea, the habitats of which 
are the nests of ants, either of the genus Azteca or 
Camponotus. 
A CAREFUL account of the different trees which have 
passed under the name of Brazil wood, and 
afford the valuable red dye, is given in Kew 
Bulletin No. 9. The Brazil wood of the fourteenth 
and fifteenth centuries came from the East, and was 
no doubt derived from Caesalpinia sappan. It has 
recently been replaced largely by the West African 
camwood, Baphia nitida, Some eight trees have at 
different times been known under the names Brazil or 
Braziletto, and in addition to those mentioned, namely, 
C. echinata from Brazil, C. brasiliensis, C. bahamen- 
sis, and C. bicolor from Peru and Colombia. Then 
there are Peltophorum brasiliense from Jamaica and 
Cuba, a very useful timber tree, and» Haematoxylon 
Brasiletto, which is a native of Colombia, Venezuela, 
and Central America, and may prove to be a valuable 
article of commerce in Colombia. Finally, there is 
the well-known logwood, Haematoxylon campechianum, 
a native of Yucatan and British Honduras, which has 
been largely planted in the West Indian islands and 
elsewhere. A long account of the early traffic in this 
wood is given, and the article is illustrated with figures 
of the pods of all these valuable leguminous trees. 
In American Forestry for December a warning note 
is uttered as to the grave danger which threatens the 
extremely valuable white and five-leaved pines of New 
England and Canada from the spread of the ‘ pine 
blister disease," which is making alarming headway, 
being spread by infected currant and gooseberry. 
bushes, both wild and cultivated. In south-western 
Maine 85 per cent. of the trees are infected, and of 
these 50 per cent. are either dead or doomed. Profit- 
ing by the devastation caused by the chestnut blight, 
which was neglected on its first appearance, legisla- 
tion of a drastic character is being framed to cope 
with the menace. In the same issue the Hon. David 
Houston justifies the decision of Congress to take and 
NO. 2467, VOL. 98] 
NATURE 
’ 
[FeEBruary 8, 1917 
keep control of all forest land for the ‘regulation of 
timber: production and watershed protection 
purchased by the Government. 
Dr. F. Du Cane Gopman has presented to the 
British Museum (Nat. Hist.) some fragments of a 
second skull of Eoanthropus dawsoni, which were 
found by the late Mr, Charles Dawson in 1915 im the 
Piltdown gravel of a new locality. The specimens 
will be described by Dr. Smith Woodward in his 
fourth paper on Piltdown Man, which is to be read 
at the next ordinary meeting of the Geological Society 
on February 28. { 
Dr. CuHartres D. Watcott has published a thir 
part of his valuable and exhaustive work on Cambrian 
Trilobites, chiefly from North America and China 
oo ire Miscellaneous Collections, vol. Ixiv., 
No. 5). 
with twenty-three plates, and a glanoe over the figures 
enables one to realise the extraordinary diversity of the’ 
Trilobites in the very early fauna to which the species 
represented belong. The genus Corynexochus is of 
special interest to the geologist in Canada, as afford- 
ing a means of correlating the Lower Cambrian rocks 
in the St. Lawrence-Newfoundland area with those of 
Mount Whyte, in the Canadian Rocky Mountains. 
Tue need for extreme caution in generalisations 
in geography, especially im human geography, 
may well be insisted on, and forms the subject of a 
paper by Mr. G. G. Chisholm in the Scottish Geo- 
graphical Magazine, November, 1916 (vol. xxxii., 
p- 507). Mr. Chisholm’s paper is a closely reasoned 
argument illustrated by generalisations, which he 
feels merit criticism, quoted from Ratzel or other more 
modern geographical writers. He draws an impor- 
tant distinction between influences which act inde- 
pendently of man’s will, and others which do not. 
The latter are affected by so many unknowable circum- 
stances that they can never be stated except in approxi- 
mate terms. The failure to distinguish these two classes 
of laws has been a most fruitful source of confusion 
in geography. Secondly, Mr. Chisholm reminds his 
readers that the value of geographical conditions 
varies with the circumstances of the time, and, 
thirdly, that statements in human geography, when 
the human will is concerned, are all the more likely 
to approach the universality of an absolute law the 
more imperious is the urgency that leads to the be- 
haviour on the part of man that is taken for granted 
in the statement. Lastly, he dwells on the danger 
of laying too great stress on any one cause affecting 
human development to the neglect of others. 
Tue abnormal ice conditions around Spitsbergen in 
1915 and 1916 are discussed by M. Adolf Hoel, of the 
University of Christiania, in an article in La Géo- 
Sraphie, vol, xxxi., No. 3. The question is not only 
of interest in relation to the weather experienced in 
north-western. Europe in these years, but of great 
importance in respect of the growing economic develop- 
ment of Spitsbergen. In the summer of 1915 stron 
easterly winds caused the ice to drift round Sou 
Cape and block the west coast until August. Vessels 
had some difficulty in entering and leaving Icefjord. 
Late in August more ice arrived by the same route and 
caused difficulties in September. This is very unusual. 
On, the other hand, the same easterly winds caused — 
the east coast of Spitsbergen to be more open than it 
has been any year since 1898. In the middle of August 
a vessel had no difficulty in traversing Hinlopen Strait — 
from the north, and reached the extreme east of 
North-East Land, Further east, towards Hope Island 
and Franz Josef Land, the sea was singularly clear 
tion, and to_ 
this end ;large areas of. forested land are now’ being” 
It is illustrated in the usual excellent manner. 
Se ow 
————oeoeeeoae ee 
