March 13, 1903.] 



SCIENCE. 



435 



both receive adequate attention. The oases 

 of Souf are in a region of dunes, the ' erg ' 

 of the Algerian Sahara, separated from other 

 settlements by several days' journey; every- 

 thing here depends on removing the sand until 

 the surface is lowered near enough the ground- 

 water to enable date palms to grow; the 

 heaped-up sand-ridges are as high as the tree 

 tops, and as the wind blows the sand freely, 

 continual labor is necessary to keep the gar- 

 dens free from drifts. Yet under these 

 highly adverse conditions, the oases contained 

 in 1899 an industrious population of 22,620 

 souls, owning 6,979 camels, 24,510 sheep, 27,- 

 864 goats, and 192,152 palm trees. The Soafas 

 have become expert trailers, for nothing can 

 cross the sands without leaving a track. 

 Theft is, therefore, less common here than 

 elsewhere in the desert, for the thief can be 

 so easily followed and discovered that thieving 

 does not pay. 



The oases of M'zab are in the stony desert 

 or ' hammada ' of a calcareous plateau. Here 

 wells are dug in the valleys, and water is 

 raised day and night for irrigation; rain is 

 stored in reservoirs and led about in canals. 

 The gardens have a luxurious vegetation; 

 dates, figs and other fruits are produced. The 

 population of seven M'zab towns in 1896 was 

 25,254 souls, owning 490 camels, 5,732 sheep, 

 3,837 goats, and 166,261 palms; besides these 

 there are 5,795 semi-nomads with a much 

 larger property in live stock. A fine palm is 

 worth $100 or more; many of the Mozabites 

 are rich. From both of these crowded popula- 

 tions emigrants go out northward to less arid 

 lands. Tor both groups of oases Brunhes 

 emphasizes an important fact: the people are 

 not savages supplying their simple wants in 

 a rudimentary manner; they are in an ad- 

 vanced stage of culture, their arts are highly 

 elaborated, and are wonderfully adapted to 

 making the best use of unfavorable surround- 

 ings, and their caravans maintain an active 

 trade across the desert. 



THE OTHER HALF OP GEOGRAPHY. 



If geography be concerned with the relation 

 of the earth and its inhabitants, and if physi- 

 ography be taken as the study of the physical 



environment of life, or the inorganic half of 

 the total subject, it is apparent that there 

 is no convenient name for the other half, in 

 which the response of the inhabitants to their 

 environment is considered. It is also true 

 that there is to-day no well-organized and 

 systematic treatment of the other half, al- 

 though partial treatments abound, especially 

 of the human elements of the subject, as in 

 the works of Ratzel. There is good reason 

 for thinking that the progress of geography 

 in the century now opening will remedy these 

 deficiencies; that the organic responses appro- 

 priate to many kinds of environments will be 

 carefully collected and classified; that the at- 

 tention of the geographical observer will be 

 equally directed to both halves of his sub- 

 ject; and that geography will be greatly bene- 

 fited thereby. 



The preceding note gives a good example 

 of a curious response to a desert environ- 

 ment, reaching even the moral sense. The 

 rapid development of the study of physiog- 

 raphy in olir national surveys of the western 

 semi-arid region, where the relation of struc- 

 ture and form is laid bare, exhibits a response 

 of an intellectual kind to a climatic environ- 

 ment. Lugeon has suggested that it is not 

 — as some have thought — an inherent spirit 

 of independence in the Swiss that prompts 

 them to maintain separate organizations in 

 the minute village communities of the Alpine 

 valleys, but that the physiographic opportunity 

 for village settlements requires the develop- 

 ment of many small communities instead of 

 a few larger ones, and thus aids in the de- 

 velopment of the spirit of independence. 

 Fewkes has given an admirable example of 

 the response of religion to environment in 

 the ' Tusuyan ritual ' (Smithsonian Bep., 

 1895, 683-700). The systematic exploration 

 and analysis of this phase of geography de- 

 serves much more attention than it has yet 

 received. A fuller consideration of this as- 

 pect of the subject is given in two essays by 

 the undersigned : ' Systematic Geography ' 

 {Proc. Amer. Phil. Soc, XLL, 1902, 235-257) 

 and ' The Progress of Geography in the 

 Schools ' (Nai. 8oc. 8ci. Study Education, I., 

 Pt. II., 1902, 7-49). W. M. Davis. 



