April 4, 19 18] 



NATURE 



95 



servations has led the authors to the conclusion that 

 the nocturnal periodicity of the larvae is primarily de- 

 pendent upon periodic variations in the arterial supply 

 of larvae to the cutaneous vessels. The periods of sleep 

 and activity of the patient were reversed, and there 

 resulted a gradual change in regard to the period of 

 the cutaneous immigration of the larvae. After four 

 days the maximum concentration of the larvae in the 

 cutaneous vessels had been changed from midnight to 

 6 a.m., and after eleven days to midday. Graphs 

 showing the number of larvae per c.c. of blood passed 

 in the urine reveal the existence of a regular periodicity 

 corresponding with that of the larvae in the cutaneous 

 blood, with the difference that the time of maximum 

 concentration of larvae in the renal and vesical vessels 

 was several hours later. Messrs. Malins Smith and 

 Matthews give, in the same number of the Annals, 

 further records of the occurrence of intestinal protozoa 

 in non-dysenteric cases. Their results show that 

 among the 200 returned soldiers examined in Liverpool 

 Entamoeba histolytica was present in twelve of the 

 158 cases, with no previous history of dysentery. 



Dr. N. A. Cobb, of the United States Department 

 of Agriculture, has published (in Nematology, vol. 

 III., pp. 431-86) an account of the nematode genus 

 Mononchus. The genus is of world-wide distribu- 

 tion, and some of the species are cosmopolitan. 

 Mononchs are regularly present in arable land of a 

 sandv or loamy nature, and sometimes occur in great 

 numbers ; the author estimates that there were at least 

 thirty millions per acre in the top six inches of a 

 field of maize in New Jersey. Most mononchs are 

 carnivorous ; they have been found to feed on pro- 

 tozoa, on rotifers, and on other nematodes. One cosmo- 

 politan species was found by the author in Florida 

 feeding on the larvae of Heterodera radicicola, a serious 

 root-pest, and it is sugrgested that further investiga- 

 tions may reveal the possibility of utilising mononchs 

 to reduce the enormous losses in crops due to plant- 

 infesting nematodes. A description of the characters 

 and anatomy of the genus is given, and it is stated 

 that the females of many, probably of most, species 

 are really hermaphrodite, the gonad producing also 

 spermatozoa, which are so minute that they have 

 apparently hitherto escaped notice. Males, if found 

 at all, are nearly always rare, and of most of the 

 sj)ecies males are not known. A key is provided to 

 the subgenera and to the fifty-seven sf)ecies — including 

 twenty-eight described as new in this memoir — and the 

 text has seventy-five excellent figures. 



RAINFALL DISTRIBUTION OVER 

 FRANCE.' 



THIS is the first portion of a contemplated large in- 

 vestigation into the rainfall distribution over 

 France, and deals with the regime over the North- 

 West Provinces. Other memoirs will contain a dis- 

 cussion of the data for the south-west, north-east, and 

 south-east of the coqntrv for the fifty years 1851-1900. 

 In the work under notice, which is an extract from 

 the memoirs of the French Central Meteorological 

 Office, full particulars are given of the data used in 

 compiling the maps of average rainfall based on a 

 fifty years' normal, bv a comparison of short-period 

 data with standard stations, affording records for the 

 complete series. In some cases the standard stations 

 seem to be at a considerable distance from the short- 

 period record to be corrected to the fifty years' normal. 

 The variability of rainfall based on records for sixteen 

 stations in France and adjacent countries during the 



1 "Etudes siir le Climat de la Franre. Regime de« Pluie«. Premie'e 

 Partie. Consid^rat'on'; gene-ales : Region du nord-ouest," Par M. Alfred 

 Angot. Pp. 128-I- 13 plates. 



2527, VOL. lOl] 



I second half of last century is discussed, from which it 

 I is shown that the departures of individual years from 

 the normal are in accordance with the theory of prob- 

 abilities. A list of the stations arranged in river basins 

 is given by departments, along with the altitude and the 

 I period of observation. Monthly isohyetals are drawn 

 ! at intervals of 10 mm. up to 100 mm., but at 120 mm. 

 j and 150 mm. thereafter, while on the annual rrfaps 

 I the intervals extend to 100 mm. A summary of the 

 leading features governing the rainfall distribution is 

 I given for each month and for the year. 



In almost all the regions considered October is the 



j wettest month, the rainfall exceeding 100 mm. in the 



! country of Caux, the department of the Manche, the 



j western part of Brittany, and the heights of Gatine, the 



i maximum being 151 mm. at Saussemesnil ; while the 



j driest areas in this month are the middle valley of 



I the Seine, the basin of the Eure, and on the Beauce,. 



I where the rainfall is between 50 mm. and 60 mm., 



I but not under the former value. The driest month is. 



February, not only as regards the actual quantity, but 



also taking into consideration the shortness of the 



month. 



For the whole year the driest regions are the basinsv 

 of the Seine, the Loire, and the Oise, where the pre- 

 cipitation varies between 500 mm. and 600 mm. The 

 stations where more than one metre of rain falls are 

 extremely few, and are mostly located in mountainous 

 areas, the maximum being 1181 mm. in the Monts 

 d'Arri^e. No detailed description appears of the 

 methods of mapping the material utilised. Rivers are 

 shown, but towns, railways, and departments are not 

 indicated, nor are the orographical features shown. 

 The maps clearly indicate the very patchy distribution 

 of rainfall, and have evidently been drawn with much 

 care. The originals were on a scale of i : 1,500,000, 

 or twenty-two miles to an inch, and then reduced for 

 publication on a scale of thirty-nine miles to an inch. 



MINERAL PRODUCTION OF PERU AND 



THE PHILIPPINE ISLANDS. 

 'T'HE official report upon the mineral production of 

 •'■ the Philippine Islands for the year 1915 has 

 recently been issued by the Division of Mines, Bureau 

 of Science, of the Government of the Philippine Islands. 

 The importance of the gold production far outweighs 

 that of any other mineral ; its value is returned as 

 2,633,528 pesos, say about 274,000^., being an increase 

 of 12- 1 per cent, above that of 1914. The gold 

 bullion, of course, also carries a certain amount of 

 silver, which is valued separately. The only other 

 metallic product is iron, of which ninety-six tons ap- 

 pear to have been produced, this being only about one- 

 half of the production of the previous year. This 

 iron is all produced in small native furnaces, and is 

 worked up into ploughshares or similar articles ; the 

 main reason in the falling off is the competition of 

 inferior articles, made from scrap-iron. There is no 

 production of native coal, none having been worked 

 since 1912. The other minerals, of which returns are 

 included, are salt, sand and gravel, clay products, 

 stone, lime, and mineral waters. The total value of 



j nil thesf' is estimated at rather less than the value of 

 the gold output. 



j The mineral statistics of Peru for the year 1915 

 show a considerable increase in most of the products 

 according to the report (No. 83) recently published in 

 Lima. The total value is given as 5,930,000?., being 

 an increase of 42 per cent, above that of 19 14. This 

 increase is due in part to the important rise in the 

 value of mineral products, but it must be noted that 

 this rise did not extend to the value of silver, and as. 



