i8 



NATURE 



[March 2, 1916 



parts is only about lo in. per annum. The valley 

 possesses considerable mineral wealth, including gold, 

 copper, lead, iron, turquoise, coal, and gypsum. The 

 metalliferous deposits, especially gold, have been ex- 

 tensively worked. But, from an agricultural point of 

 view, the district has been practically neglected. Vast 

 tracts of arable land, capable of producing valuable 

 crops, lie uncultivated for lack of treatment. In any 

 system of development, artificial irrigation would, of 

 course, be a necessity, but there are abundant stores 

 of underground water available for exploitation and 

 use. As in south-eastern Nevada, these supplies are 

 more prolific in the "valley-fill" than in the "bed- 

 rock." The most important sources are the sand and 

 gravel deposits, which lie in irregular lenticular masses 

 at different depths in different localities. The Creta- 

 ceous rocks, however, underlying the eastern portion 

 of the basin, yield a sufficient supply for domestic 

 and cattle-raising purposes. 



Further to the west lies the great State of Cali- 

 fornia, second only to Texas in point of size, and 

 characterised by a remarkable physiographical diver- 

 sity. Thus it encloses both the highest and the lowest 

 levels in the Union, viz., 14,501 ft. above the sea 

 (Mount Whitney), and 276 ft. below the same datum 

 (Death Valley). There are equally diverse hydro- 

 graphic features. In the southern deserts is to be found 

 the extreme of aridity : a rainfall which averages less 

 than 3 in. per annum, and, in some years, is merely 

 a trace ; whereas, in the north-west, there is very 

 heavy precipitation, amounting to an annual average 

 of close on 100 in. at certain stations. Mr^ Waring's 

 paper contains a very full account of the natural 

 springs scattered throughout the State, with an in- 

 teresting study of their occurrence and yield. The hot 

 springs are perhaps the most remarkable class, and 

 these include all springs having a temperature higher 

 than about 90° F. Other groups of springs include 

 carbonated springs, sulphur springs, saline springs, 

 magnesic springs, and iron springs, each class named 

 after the constituent which marks the flavour and char- 

 acter of the water. One curious spring is the so- 

 called " poison spring " on the western border of Death 

 Valley, which is an arm of the Colorado Desert. It 

 yields a salty water, impregnated probably with 

 sulphates, producing a strong feeling of nausea in 

 anyone imbibine it. Other popularly described 

 " poison " springs are believed to contain arsenic, but 

 of this there is some doubt, as arsenic is a rare con- 

 stituent of water and seldom present in measurable 

 amount. 



The most prominent topographical feature of Cali- 

 fornia is the Great Central Valley, 16,000 square miles 

 in area, flanked on each side by mountain ranges 

 running parallel with the coast. One portion of this 

 is the Sacramento Vallev, a broad and fertile, plain 

 lying between the Sierra Nevada and the Coast Range. 

 It Is a district unmistakably adapted to agricultural 

 pursuits, possessing climatic conditions of the most 

 favourable kind. The winters are moderate, and the 

 rainfall, which averages from 20 to 25 In. annually. Is 

 concentrated. In a large measure, within the five 

 months of their duration. The orchard Industry has 

 acquired special prominence. All deciduous fruits bear 

 heavy crops, being rarely damaged by frost, while the 

 more delicate varieties, such as apricots, almonds, 

 olives, etc., flourish In suitable localities. Under 

 normal conditions it Is quite unnecessarv to resort to 

 artificial Irrleratlon, but, as a means to the more ex- 

 tended and Intensive cultivation of ground crops and 

 the Inclusion under operation of certain lands at pre- 

 sent only available for grazing, the study of water 

 storage and distribution Is recelvintr attention. The 

 ground water Is princlpallv contained In the upper- 

 most alluvial deposits, and the valley is remarkable 

 NO. 2418, VOL. 97] 



for the large area in which the water-level stands near 

 the surface of the ground. The alluvium is of two 

 periods : an older deposition dating from the Pliocene 

 epoch and cxjntinuing into the Pleistocene, and a later 

 deposit of more recent formation. This latter is the 

 most productive water-bearing stratum, and consists 

 largely of sands and gravels in an uncemented con- 

 dition. The total quantity of ground water in the 

 valley is undoubtedly very considerable, and the appli- 

 cation of irrigation from this source presents great 

 possibilities of development. 



Adjacent to the Sacramento Valley, on the eastern 

 side of San Francisco Bay, is situated a somewhat 

 notable cone of alluvial deposit, built up by a neigh- 

 bouring creek, and called, from its proximity to a 

 town of the name, Niles Cone. The cone proper is 

 11,800 acres in extent, but a marsh tract adds 9000 

 acres to the area forming the ground-water dTstrict 

 covered by Mr. Clark's report. The creek from which 

 the cone derives its origin Is Alameda Creek, at the 

 outlet of the Santa Clara Valley. This receives the 

 drainage of 640 square miles of mountains and in- 

 terior valleys. The alluvial deposits have been brought 

 down by streams during periods of irregular flow. 

 The upper layers belong to the Pleistocene and Recent 

 series of the Quaternary system ; the lower strata form 

 part of the Orinda formation In the Pliocene series. 

 Below these fresh-water deposits lie shale and sand- 

 stone of the Cretaceous, and, possibly, of the Jurassic 

 periods. The development of artificial Irrigation is 

 proceeding rapidly, and numerous wells have been 

 sunk during the past few years, but the limit of yield 

 from the ground water has almost been attained, and 

 any further supplies will have to be obtained by con- 

 serving the large quantities of flood water which have 

 hitherto been allowed to run to waste. B. C. 



SOME RECENT STUDIES ON PROTOZOA 

 AND DISEASE. 



T^R. J. W. SCOTT MACFIE describes in Annals 

 ■•-^ of Tropical Medicine and Parasitology (vol. ix., 

 No. 4) a number of interesting protozoa from Accra, 

 West Africa. He records the occurrence of a piro- 

 plasm — Nuttallia decumani, n. sp. — in the blood of 

 brown rats, and gives an account of a case of amcebic 

 dysentery in a monkey (Cercopithecus), in which 

 numerous Entamoeba were present, together with a 

 vast number of minute splrochastes. He designates 

 as a new variety (var. equinum) a strain o7 Try- 

 panosoma congoiense, chiefly on the ground that in 

 many of the trypanosomes the trophonucleus lies near 

 the anterior end. The clinical aspect of the disease 

 produced by this trypanosome in the original host — a 

 mare — was also peculiar in that there appeared on 

 the skin of the body raised disc-like patches or 

 plaques, which, however, disappeared after about 

 three days. Dr. Macfie also records observations on 

 two mules suffering from a form of trypanosomiasis 

 clinically resembling acute dourine, and states that in 

 these cases infection by coitus — the usual method of 

 transmission of this disease — may be excluded with 

 certainty. 



An account of researches by Drs Fantham and 

 Porter on induced herpetomoniasis in birds appears in 

 the same number of the Annals. Water-scorpions and 

 gnats, in the intestine of which the flagellate parasite 

 Herpetomonas was present, were fed to birds — 

 canaries, sparrows, and martins. A fatal Infection of 

 the birds ensued, and herpetomonads, flagellate and non- 

 flagellate, were found in the internal organs (liver, 

 spleen, bone-marrow, etc.). The disease ran either an 

 acute or a chronic course. In acute cases the flagel- 

 late form of the parasite was more common in the 

 birds at death, while In chronic cases the non- 



