November 24, 1910J 



NATURE 



III 



animal. They have been absolutely exterminated by 

 hunting, trapping, or by the decrease of the food- 

 supply which occurred in the years 1904-5." An in- 

 teresting cause is the disappearance of the rabbit. 

 In 1904-5. "some disease smote the rabbits, and they 

 died off by thousands." "In consequence of their dis- 

 appearance, the animals which fed on, them^the fox 

 (the wolf, which need not be counted), the marten, 

 the chief food of which, however, is. mice, and other 

 animals — died from absolutely no other, cause than 

 starvation." The problem of the conservation of the 

 water supplv is curiouslv bound up with afforestation. 

 For instance, it has been found necessary to conserve 

 the timber on the east slopes of the Rockies in order 

 to conserve the river-heads. "It was. shown that the 

 destruction of the timber meant the disappearance of 

 the regular water supply of those provinces, the agri- 

 cultural production of which is the pride and the hope 

 of Canada." 



A list of the committees shows the scope of the 

 Commission. They are seven, in number, viz. : — 

 Fisheries, game, and fur-bearing animals; forests; 

 lands; minerals; waters and water powers; public 

 health ; press and cooperating organisations. Their 

 reports on the first year's work, the chairman's speech, 

 and the discussions are of unusual interest. Recom- 

 mendations to Government have already commenced. 

 Such a scheme for the scientific control of the ultimate 

 natural resources of a country must inevitably be 

 adopted elsewhere. 



It has, however, one serious deficiency as yet, the 

 absence of any organisation for the preservation of 

 those sites and objects that have no commercial value, 

 but the scientific and artistic importance of which is 

 verv great. Such conservation could easily be worked 

 in with the main business. The latest reports of the 

 committees for this special purpose in Germany are 

 to hand. There are official directions giving the 

 least injurious method of picking flowers. Every dis- 

 trict seems to be thoroughlv looked after and studied 

 bv its committee. There are verv interesting maps 

 of the habitats of rare plants, and studies of typical 

 fauna, such as that by Dr. Kuhlgatz, on the animal 

 life of the moors in 'Neulinum. Reference to maps 

 shows that the districts preserved are remarkably 

 numerous. The movement is not merely govern- 

 mental, but aims at enlisting the sympathetic coopera- 

 tion of the people. The propaganda is now being 

 extended to the schools, and Prof. Schaefer-Cassel has 

 an eloquent address on the subject. Cases for the 

 "pillory " are recorded, as, for instance, that of a man 

 who in a few vears annexed qoo specimens of Cypri- 

 Peditim calceoliis. This flower, once found near 

 Settle, in Yorkshire, and perhaps in one or two other 

 sites, has now, I understand, disappeared from this 

 country. The same fate will attend many a rare 

 plant, butterfly, or bird, unless we. too. adopt some 

 svstem of preservation. The Wild Birds' Protection 

 Act, it is to be feared, is a dead-letter. 



If we had a national commission for the protection of 

 all " monuments of nature," including beauty spots, 

 places interesting for historic or geological reasons, 

 woods, vallevs, and hills remarkable for some species 

 of plant, animal, or insect, we should not be a "nation 

 of shopkeeoers." But is the United Kingdom too far 

 exploited for a commission for the protection of its 

 /latural resources, including its natural history? There 

 would be difficulties in the way, but surmountable 

 difficulties. One very obvious fact presents itself at 

 once — these places of beauty, these habitats of species 

 (bv no means useless for the ends of commerce, since 

 thev subserve the ends of science), are precisely those 

 which defv culture and would never make it worth 

 while. To make them into natural museums would 

 be a work for which future trenerations would be more 

 NO. 2143, VOL. 85] 



grateful than we can realise. The museum of brick 

 and stone has its uses ; zoos and botanical gardens are 

 of no little value ; but neither can compare, either for 

 interest or for scientific study, with a reservation. 

 Not only Geirnany, but .\ustralia, is setting an ex- 

 ample here. Dr. Conwentz's book, recently published 

 in England, and an excellent article by Dr. Giinther 

 in the .\' aturwissenschaftliche Wochenschrift of August 

 7 last, give a luminous exposition of the principle and 

 its results. 



In time perhaps the world will be full of such spots, 

 where nature may have her Sabbaths and preserve 

 her most interesting children, among whom, last but 

 not least, will be aboriginal varieties of man himself. 

 Is there not a reservation for the tribes of Central 

 Australia? A. E. Crawley. 



AGRICULTURE IN THE DRY REGIONS OF 

 THE BRITISH EMPIRE.^ 



THE ordinary farm crops on which the supply of 

 food-stuffs depends seem to be produced best in 

 regions where the rainfall varies between 20 and 35 

 inches per annum. Where the upper limit is exceeded 

 in the British Islands, a good deal of pasture is 

 found ; on the other hand it is notable that the great 

 wheat-producing districts, the eastern counties, are 

 regions where the rainfall comes nearer to the lower 

 limit. Special agricultural methods become necessary 

 where there is less than 20 inches of rain, as is the 

 case over large areas in Canada, Australia, India and 

 South Africa. These methods fall into two groups : 

 irrigation is required if there is less than io inches 

 of rain, while special cultural operations, collectively- 

 known as "dry farming," are used when there is 

 as much as 15 or more inches. Between 10 to 15 

 inches, sometimes the one and sometimes the other 

 method proves the more economical. ; 



" Dry-farming " methods are of great interest to. the 

 student of soil phvsics. Their object is to keep the rain 

 water near the surface of the soil and to prevent loss, 

 bv evaporation, bv surface drainage, arid, if possible, 

 bv percolation. A remarkable degree of success- 

 appears to be attained. An examination of the 

 methods in vogue in different parts of the world shows 

 that all have certain features in common. The land 

 is ploughed up in a roup^h state and the subsoil com- 

 pacted directly after harvest' or before the rainy 

 season, if there is one; in countries where the raiir 

 is unevenlv distributed and torrential downpours 

 occur, rather elaborate terracing is arranged to pre- 

 vent any loss by running off the surface; any streams 

 that form having to follow a sinuous course over the 

 whole field, so that absorption may be as complete 

 as possible. Directlv the rain is over, the surface soil 

 is thoroughly stirred, thereby losing a little water by 

 evaporation, but forming a loose layer. The water 

 is thus imprisoned between the compacted subsoil and 

 the thin loose layer of surface soil. The greatest 

 importance is everywhere attached to the maintenance 

 of this loose laver on the top ; cultivation is repeated 

 as often as rain" has fallen, or whenever for any other 

 reason it is considered the layer has become compact. 

 Incidentallv this repeated cultivation has the effect of 

 keeping down weeds, which, if unchecked, would use 

 up a good deal of the water. 



In the drv parts of Canada and the United States, 

 where these methods are most highly developed, it is 

 customarv to take a crop — usuallv wheat — once in two 

 years onlv. leaving the land fallow in the alternate 

 year. It is considered that two-thirds or even more 



1 Transvaal Agricultural Jovrnal, vol. vir., igio. 

 Agricultural Journal of the Cape of Good Hope, vol. xxxvi., igio. 

 "Water Requirements of Crops in InHia." By J. W. Leather. (Memoirs 

 of the Department of Agriculture in India.) 



