322 



NA TUBE 



[August 6, 1908 



Hie author points out that there is a great deal of 

 work still to be done, especially among the reptiles 

 and the marine fishes. There are blanks, too, in the 

 general record that it has been impossible to fill owing 

 to the lack of resident observers. The records from 

 Snowdonia and the central moorlands, for example, 

 are derived almost entirely from the observations of 

 naturalists who have visited those districts froin time 

 to time, and there are few or no winter records from 

 these districts. The author proposes to publish addi- 

 tional records in the form of a supplement. We 

 might suggest instead of this a new edition in two 

 or more volumes, with more space and greater detail 

 and the authority for the statements, which should 

 always be given in a compilation. 



Mr. Forrest has carried out a difificult and laborious 

 task so well that we feel he might well undertake a 

 work which would be monumental as a history of the 

 vertebrate fauna of the most interesting (from that 

 point of view) part of these islands. It was not to 

 be expected that many of the rare stray avian visitors 

 which straggle to our shores would penetrate so far 

 as Wales. Nor are its shores patrolled day after 

 day, in season and out, by men with guns on the 

 look-out for a rarity, as are parts of our east and 

 south coast. Two hundred and seventy-two species of 

 birds are enumerated. But it is in its breeding 

 species that the richness of the North Wales avifauna 

 consists. The author states that 143 species have 

 been known to breed in the district. They, do not all 

 do so now; but it has a list of 126 annual breeders, 

 although its total area is not much more than half 

 that of Yorkshire, which, despite great diversity of 

 physical features, can only claim three less. 



Treating of the Welsh names, which are dealt with 

 very fully, the author states that his aim has been 

 to include only those which are actually used by the 

 people of the district; " ' book ' names are excluded." 

 We cannot, however, regard some of the names given 

 as other than book names. The honey buzzard, for 

 instance, seems tar too rare to have a genuine Welsh 

 name ; the same may perhaps be urged in the case of 

 the black-tailed godwit, and there seems no reason 

 why it should be called "black plover." Again, if 

 the Welsh locally distinguished the Arctic from the 

 common tern at all, there seems no reason why they 

 should have pitched upon a word meaning Arctic or 

 northern unless they had been influenced by books. 

 Nor can we agree with the author (while giving full 

 weight to his authorities) in rendering barcud as kite. 

 Bergut or bearcoot is the name for an eagle among 

 the Kirgiz Tartars, and the buzzard is really an eagle, 

 while the kite is not. Moreover, we have, according 

 to Eugene Rolland, barged and barguet for the buz- 

 zard in Breton and Breton Armoricaine, but no name 

 like it for the kite in those branches of the Celtic 

 language. The bird of which Giraldus Cambrensis 

 and his companions heard the sweet notes between 

 Carnarvon and Bangor was not in all probability a 

 golden oriole. Giraldus says " of a bird, which some 

 said was a woodpecker, and others, more correctly, 

 an aureolus. " He was not the last to mistake a green 

 woodpecker for an oriole. The misprints are so few 

 that there is no sheet of errata et corrigenda. Had 

 there been, perhaps the unfortunate blunder about the 

 buzzard would not have gone uncorrected. The 

 statements that it rears two broods in the year, and 

 will lay again if robbed of its first clutch of eggs, are, 

 of course, the opposite of the facts. A map of so 

 diversified a district is doubtless a serious and trouble- 

 some matter, but the one given in this volume is on 

 so small a scale, and the names are printed in so 

 small a type, that it is almost useless to eyes that 

 r=5ad ordinary small print without difTiculty. 



NO. 2023, VOL. 78] 



THE WATER PROBLEM IN AGRICULTURE.' 



'P HE increasing use of artificial manures and of 

 •'■ improved tillage implements has rendered 

 possible an increase in the amount of produce ob- 

 tained from a given area of land, and attention has 

 during the past few years been directed to another 

 factor, the water supply, which at present limits crop 

 production in a number of cases. The amount of 

 water actually transpired through the crop depends 

 on too many circumstances to be stated with pre- 

 cision, but it may be roughly estimated at 300 lb. or 

 more for every pound of dry matter produced, so that 

 if two tons of dry matter is produced per acre, at least 

 600 tons of water, equal to 6 inches of rain, will be 

 used in transpiration, quite apart from what is lost by 

 evaporation, percolation, &c. A crop of this size is by 

 no means excessive ; indeed, in some types of intense 

 cultivation three times as much produce would be 

 aimed at. Even in England the problem is often 

 serious; it is far more so in countries where the rain- 

 fall is deficient during the whole or part of the grow- 

 ing season. 



In order that a large proportion of the rain-water 

 should remain near the surface of the soil within reach 

 of the plant roots, it is obviously necessary to reduce 

 loss by percolation and evaporation. The practical man 

 in dry districts has succeeded in evolving methods 

 which go some way to doing this. The methods and, 

 implements used by the Madras cultivators are de- 

 scribed by Mr. H. C. Sampson in the Agricultural 

 Journal of India. In some districts recourse is had to 

 deep ploughing with a heavy plough, followed by a 

 lighter plough, and then when the crop is up the land 

 is hoed. In other districts the plough is the only til- 

 lage implement. But in practically all cases the plan 

 is to stir the surface of the soil after a rain, and 

 to keep the top soil loose during the growth of the 

 crop. The methods adopted in the arid regions of the 

 United States are described in the Transvaal Agricul- 

 tural Journal (April, 1908) by Mr. Macdonald, and in 

 the Journal of Agriculture of South Australia (March, 

 1908) by Mr. Straw-bridge, who was sent with the 

 express purpose of reporting thereon. The)' include 

 deep ploughing, followed by harrowing, so as to get 

 the soil into a fine state ; the harrowing is, as a rule, 

 repeated after each rain. When the crop is up the 

 surface soil is frequently stirred. It seems definitely 

 established that when the top layer of soil is in a loose 

 condition it retains water better than if it is compact, 

 but the loose condition must be maintained by constant 

 stirring. 



The gain m water content may probably be ascribed 

 to decreased evaporation, for water evaporates less 

 freely from loose than from compact soil. The ex- 

 planation usually given is that the movement of water 

 in soils (apart from the gravitational flow) is a sur- 

 face-tension effect akin to the rise of water in capillary 

 tubes, and is therefore facilitated when the spaces be- 

 between the particles are diminished, and impeded 

 when the spaces are kept large. Frequent stirring of 

 the soil, which prevents it becoming compact, reduces 

 the capillary movement of water to the surface, and 

 consequently lessens the evaporation. This hypothesis 

 explains a good deal, but unfortunately it has not 

 been very fully developed; there is little doubt that if 

 some physicist would take the matter up he could 

 obtain results of great importance to agricultural 

 science and practice. 



1 (t) The Agricultural Journal of India, vol. iii., part i. (190S.) 



(2) Memoirs of the Department of Agriculture in India, vol i , No. 6, 

 " The Loss of Water from Soil during Dry Weather," by J. W. Leather. 



(3) The Transvaal Agricultural Journal, April. igoS. 



(4) The Journal of the Department of Agriculture of South Australia, 

 March and May, 1908. 



