. AuGUST 20, 1914| 
the English Channel and extending close to lat. 
80° S. The greater portion of the stations were for 
plankton-collecting, but the list includes a certain 
number of localities at which specimens were obtained 
by the shore-party. During the first sorting of the 
collection a system of numbering was adopted which 
has not proved suitable for more permanent use, and 
these provisional station-numbers, which are entered 
in the third column of the tables, have accordingly 
been replaced by others, which occupy the second 
column, and correspond with those in the maps. The 
-plankton-nets used are referred to the number of 
meshes per linear inch, the ‘‘full-speed net” having 
no fewer than 180. 
IN continuing his article on pattern-development 
among mammals and birds in the August number of 
the American Naturalist, Dr. G. M. Allen suggests 
that the light-coloured rump-patch so common among 
ungulates, and generally regarded as a “‘ recognition- 
mark,’ is probably due to the total inactivity of the 
primary pigment-patches usually covering that region 
of the body. Among the ground-squirrels, or chip- 
munks, a transition may be observed from a uniformly 
grizzled coat to one indistinctly spotted, then to one 
with rows of white spots, and finally to others with 
broken or complete longitudinal white stripes. Such 
stripes the author believes to be due to the develop- 
ment, not of breaks between the primary pigment- 
patches, but of small pigmentless spots, which, in their 
fullest intensity, unite into stripes. On the other hand, 
it is quite conceivable that the reverse condition—the 
breaking up of stripes into spots—may likewise occur 
in some instances. 
In ‘‘A Fourth General Adjustment of the Precise 
Level Net in the United States and the Resulting 
Standard Elevations,” by W. Bowie and H. G. Avers 
(pp. 328; Special Publication No. 18; Washington : 
Government Printing Office, 1914), the results of the 
latest adjustment of the level net of the United States 
are discussed, all precise levelling done previous to 
1912 being included except those lines which do not 
form portions of closed circuits. On this occasion the 
orthometric correction has been applied to standard 
altitudes westward of the Mississippi River, since this 
correction is found to be needed in high altitudes. 
Altitudes are now given both in feet and metres, the 
former being added for the convenience of surveyors 
and engineers who may use the results. Instruments 
and method of levelling have been the same as in 
preceding years; the rate of work has varied from 
56 to 84 miles a month, according to the character 
of the country traversed, and the average cost has 
been rather above 2]. per mile. For the present pub- 
lication, after the orthometric correction had been 
applied to the levelling westward of the Mississippi, 
an adjustment of the entire net was made, using the 
weights as determined by the 1907 adjustment. A 
special adjustment was also made of altitudes in the 
western part of the country with very satisfactory 
results. The accidental and systematic errors of the 
levelling, which has been carried out by the Coast 
and Geodetic Survey since 1899, has, in this report, 
been computed in accordance with the resolutions 
NO. 2338, VOL. 93] 
NATURE 
651 
adopted at the Conference of the International Geo- 
detic Association, held at Hamburg in 1912, and for 
levelled lines totalling 15,028 kilometres, the probable 
accidental error is given as +o-713 mm. per kilometre, 
and the probable systematic error as +0-080 mm. per 
kilometre. It is, however, pointed out that this 
systematic error cannot include all sources of error, 
since the probable accidental error for a kilometre, as 
found in the general adjustment of 1912, is consider- 
ably larger than that obtained by the International 
formula. 
In an. interesting paper in the Popular Science 
Monthly for August Dr. William H. Ross, of the 
United States Bureau of Soils, deals with the origin 
of nitrate deposits, more particularly of the famous 
Chilean beds, which occur in the deserts of Atacama 
and Tarapaca, and still form the principal source of 
the world’s supply of nitre. In the year 1912, for 
example, the total quantity exported from Chile -was 
2,485,860 tons. The origin of these enormous deposits 
is still uncertain; the various theories which have been 
put forward to explain their existence are dealt with in 
some detail in the present paper. It has been sug- 
gested that they have been forméd by the nitrification 
of immense deposits of sea-weed, of guano, or of the 
dung of vicufias and llamas, but it is more probable 
that they represent the concentrated fertility of the 
thousands of square miles of land between the water- 
shed of the Andes and Coast Range, the nitrates 
formed in these regions being washed out by the 
periodical mountain floods, which occur every seven or 
eight years, and subsequently recovered by the 
evaporation cf the leachings in the lower levels, where 
the nitrates are found. 
Amone paleontological papers it may be mentioned 
that the latest issue of the Palaeontologia Indica 
(ser. 15, vol. iv., part ii., fasc. 4) is devoted to the 
description, by Dr. K. Holdhaus, of the lamellibranchs 
and gastropods of the Silurian Shales of Spiti, N.E. 
Himalaya, in which a number of new species, and at 
least one new genus, are named. Also that the 
Egyptian Survey Department has issued the first part 
of a catalogue of the invertebrate fossils of Egypt re- 
presented in the collections of the Museum of Geology 
at Cairo, by M. R. Fourtau. This deals with Creta- 
ceous echinoderms, a group in which the Cairo 
Museum is particularly rich, as the result of -collec- 
tions made of late years in the Sinaitic Peninsula 
between Gebel Tih and the Gulf of Suez. A consider- 
able number of the specimens represent new species, 
all of which, together with many others, are figured. 
Tue joint annual report of the Forestry Branches 
for 1912-1913 (London: Wyman and Sons, Ltd.), is 
due to a recent arrangement by which the Board of 
Agriculture and the Office of Woods cooperate in 
the development of forestry in this country. The 
report gives an excellent historical summary of the 
management of the Crown woods and forests from 
the earliest times until 1912. This is followed by a 
brief account of each of the twenty forests and wooded 
estates that are now under the charge of the Com- 
missioners of Woods. These properties, with a total 
