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NATURE 



[November 8, 19 17 



editions are here arranged in groups, for of some 

 of them there have been many issues, as, for 

 instance, that of the popular Capt. Thomas Brown, 

 which either as a new edition or as a re-issue 

 has appeared more than a score of times. A Ust 

 of separate books and reprinted articles dealing 

 with White and Selborne is added. This final 

 part also contains lists of the bibliographical and 

 biographical works which have been consulted, 

 of the periodicals cited, and of the special abbrevia- 

 tions used in the present work. 



The biographical side of the book can scarcely 

 be considered so satisfactory as the bibliographical 

 portion. To begin with, it is avowedly, and by 

 the plan of the w-ork unavoidably, incomplete as 

 a biography of British ornithologists; and, indeed, 

 it never professed to be otherwise. The aim of 

 the authors has been "to give a biographical 

 account of each author or co-author of a sepa- 

 rately published work," the result being a bio- 

 graphy of the greater part of our ornithologists 

 — and of a good many other people, too : to ^it, 

 the authors of works which mention birds, but 

 are of a worthless nature, ornithologically speak- 

 ing at all events. At the same time we miss 

 well-known names of really good ornithologists 

 who have done some of the best work, and whose 

 writings will be referred to long after more popu- 

 lar and showy books have sunk into oblivion, as 

 many of them had already done. But we miss 

 the names of these good men in the present work 

 because their published writings appeared only in 

 periodicals, transactions, and the like, and were 

 not separately published. The second portion, 

 or continuation, of the bibliography, already 

 alluded to, will, how^ever, doubtless set this 

 right and complete the biography of British 

 ornithologists. As to the biographies given of 

 living ornithologists — a delicate subject — they 

 vary greatly in extent ; and as in this respect they 

 probably depended a good deal on the amount of 

 information furnished by the subjects of the 

 respective notices, they differ greatly, as may 

 readily be imagined, in the kind, as well as in the 

 extent, of the information they afford. British 

 bird-men will read them all with considerable 

 curiosity. 



(2) Mr. Thorburn and his publishers are to be 

 congratulated on the completion, by the issue of 

 vol. iv., of this famous and beautiful set of 

 coloured plates of the birds on the British list, 

 A book which stands high in the fine arts, and 

 from its price (low as this is for all these pictures) 

 must be looked upon as one of the luxuries 

 of life, has been begun and finished during the 

 Great War. The volume now before us includes 

 the wading birds (plovers, sandpipers, etc.), the 

 terns, gulls, skuas, auks, divers, grebes, and 

 petrels. They are beautifully drawn and coloured 

 and true to Nature, though in one or two cases 

 it may seem to some people that the peculiar 

 attitudes are a little exaggerated. The colour 

 reproduction leaves little or no fault to be found. 

 But the former remark does not apply to the 

 valuable and most interesting drawing of a 

 NO. 2506, VOL. 100] 



"drumming" snipe, which, "made from sketches 

 taken in the spring of 1914 after watching the 

 bird, shows the position of the outer tail-feathers, 

 spread out and separated only during the descent,"^ 

 The letterpress notes are concise, but most use- 

 ful, informing, and very much to the point. To^ 

 those who wish to have a good coloured figure 

 of every species of bird which has ever occurred 

 in a wild state in this country, it may be said that 

 this is the only work which can satisfy them. A 

 more desirable book for the country-house library 

 or billiard-room it would be difficult to find. 



THE NUTRITION OF FARM ANIMALS. 

 The Nutrition of Farm Animals. By Dr. H. P. 

 Armsby. Pp. xvii + 743. (New York : The 

 Macmillan Co. ; London : Macmillan and Co.^. 

 Ltd., 1917.) Price 115. net. 



GREAT advances have been made in the study 

 of animal nutrition since Dr. Armsby first 

 began his investigations at the State College of 

 Pennsylvania and wrote 'his "Manual of Cattle 

 Feeding" and his "Principles of Animal Nutri- 

 tion." He has now brought together the material 

 and presented it anew. There has been no funda- 

 mental upheaval since the last edition of his earlier 

 book appeared, but there have been remarkable 

 changes in details, and in consequence the picture 

 is now very different from what it was, though 

 it is still recognisable in its main features. 



In the first section, dealing with the composi- 

 tion of plants and of the animal body, considerable 

 advances are recorded in our knowledge of the 

 lipoids, the proteins, and the non-protein nitro- 

 genous substances. 



The second section deals with digestion and 

 resorption, and gives a useful summary of the 

 American and German investigations. Consider- 

 able interest attaches to the digestion of carbo- 

 hydrates. For long it was supposed that the 

 cellulose of feeding-stuffs was indigestible : no 

 digestive enzyme was known to attack it, and there 

 seemed no mechanism for breaking it down. 

 Henneberg and Stohmann proved that it was 

 digested, and at a later date both Wildt and 

 Zuntz showed that the process occurs in the por- 

 tions of the alimentary canal where the food stag- 

 nates, i.e. in the paunch of ruminants, and in the 

 caecum and colon. Later investigations indicate 

 that it is brought about by organisms inhabiting 

 the alimentary canal, and that it gives rise to con- 

 siderable quantities of carbon dioxide and methane, 

 as well as various acids, mainly acetic and butyric. 

 These are resorbed as salts, which appear to 

 constitute the sole contribution that cellulose 

 makes to the nutrition of the animal bodv. One 

 cannot help wondering whether better use could 

 not be made of the cellulose by subjecting it to 

 some chemical or bacterial treatment before using 

 it. Apparently the pentosans are digested in the 

 same way, and also the mucilage of linseed cake, 

 according to Neville's experiments, which, how- 

 ever, the author does not mention. Bacteria cause 



