208 



SCIENTIFIC NEV\^S. 



[Mar. 2, iS 



bers of sparrows have been shot, opened, and the con- 

 tents of their crops carefully examined. On so doing, 

 it has been found that the insects form but a small frac- 

 tion in comparison with the vegetable matter. We 

 should pronounce the sparrow as the only bird to be 

 unsparingly destroyed, believing that whatever good he 

 eifects will be better executed by other hands — or rather, 

 beaks — in his absence. 



Mr. Wood writes truly enough, " We cannot obtain 

 service in this world for nothing. Work brings wages 

 as a natural corollary." But the more a bird is truly 

 our friend, the less do his wages come out of our produce. 



Among the farmers' foes rank, in the first place, certain 

 rodents, such as the rats and the mice. The original 

 home of the common rat seems_^ to have been the region 

 of the lower Volga, and it should hence be called the 

 Russian rather than the Norwegian or the Hanoverian. 



We are here told that rats might be " profitably 

 emploj'ed for culinary purposes," as it is done by John 

 Chinaman. Unfortunately these animals, however 

 delicate may be their flesh, often swarm with trichinae 

 and would hence, unless very thoroughly cooked prove a 

 highly dangerous food. 



The injurious character of the hare and the rabbit is 

 duly enforced. It will be indeed weakness if in these 

 days of agricultural depression Parliament grants a " close 

 time " for such vermin. 



We do not see that due attention is paid to the 

 squirrel, which is, in fact, a tree-rat. It spoils in well- 

 wooded districts no small quantity of pears, apples, and 

 especially wall-fruit, not " taking a little," but gnawing off 

 the sunny side of all they can find. Again, it rivals the 

 cat and the weasel as an enemy of our small birds, which 

 show evident alarm if they see one of these creatures. 

 It devours the eggs and often the young also. 



The hedgehog deserves a more laudatory notice than 

 he here receives. He is the only European quadruped 

 which can successfully engage the viper, and where he 

 has been hunted down by the combined activity of game- 

 keepers and gipsies — an unholy alliance — these snakes 

 increase wonderfully. Nor must we forget that the 

 hedgehog proves himself a " farmers' friend " by devour- 

 ing slugs, snails, and the grubs of the cockchafer. 



With the exception of the sparrow we entirely agree 

 with Mr. Wood in his plea for the small birds, and quite 

 as much, if not more, as regards the small birds of prey 

 and, above all, the owls. Had we the power, we should 

 visit the shooting or trapping of an owl, or the 

 destruction of its nest, with a minimum penalty of ^5 — 

 certainly not too high a figure in case of so useful a 

 servant of the public. 



Mr. Wood's work is rich in interesting observations, 

 and will form pleasant reading for many persons who 

 have no personal connection with the farm or the garden. 



A Treatise on Photography. By Captain Abney. London : 

 Longmans, Green and Co. Price 3s. 6d. 

 This book, which forms one of the " Text Books of 

 Science " series, is now submitted to us as a fifth 

 edition, revised and enlarged, so as to include the 

 advance of photography up to the most recent date. 

 The publishers were indeed fortunate in obtaining the 

 co-operation of a scientific photographer of such emi- 

 nence for the production of this volume. We should 

 like to quote a sentence from the short preface by 

 the author, as it emphasises a remark we made recently in 

 reviewing a photographical hand-book, and as it can hardly 



be too strongly impressed on those who make photo- 

 graphy a source of pleasure or profit. Captain Abney 

 says, " It is a matter of regret to him that amongst 

 photographers, both amateur and professional, there 

 are but few who take what may be called a scientific 

 interest in the art they practise, and it would be a source 

 of gratification to him if this work should be the means 

 of adding even a few earnest workers in the wide field 

 which is still op)en for investigation." This sentence is 

 the keynote of the whole book, and we have the why and 

 wherefore of the numberless photographical processes 

 described with a painstaking clearness that leaves nothing 

 to be desired. In the space at our disposal, we cannot 

 enter into details of Captain Abney's masterly treatment 

 of his subject ; it will be sufficient to mention that within 

 the limits of this small volume, we have descriptions of 

 nearly every known photographical process from the 

 year 1777 to the present time ; concise, of necessity, but 

 never superficial, where information can be of use to the 

 student ; and we think many photographers will date 

 their " scientific interest " in photography from their 

 study of Captain Abney's book, and so fulfil his earnest 

 wish as quoted above. 



A Manual of Orchidaceous Plants cultivated under Glass 

 in Great Britain. Part I., Odontoglossum ; Part II., 

 Cattleya and Laelia. James Veitch and Sons, Royal 

 Exotic Nursery, King's Road, Chelsea. 



This elaborate work may be considered as addressed 

 to the horticulturist rather than to the botanist. Still it 

 is impossible for the orchid family to be fairly discussed 

 without raising questions in which the student of plant- 

 life will be profoundly interested. In fact, no great group 

 of plants can be considered more instructive, and much as 

 has been done by Darwin and Miiller, very much still 

 remains to be ascertained. One of the most obvious 

 lessons here brought to the front is the light which the 

 orchids throw on the supposed fixity of species. In 

 them we recognise hybridity occurring naturally — that is, 

 without human intervention. These hybrids, further, 

 are by no means barren, but are perfectly capable ot 

 reproduction. We feel confident that if any competent 

 and conscientious naturalist, if such still exist, who holds 

 to the doctrine of the permanence of species would under- 

 take the study of this one family he would find himself 

 driven to accept the great principle of Evolution. 



We note with pleasure that the authors quote Lamarck's 

 definition of species, which we here reproduce : — 



" A collection of similar individuals which were pro- 

 duced by other and similar individuals constitute species. 

 This definition is exact, for every living creature nearly 

 resembles those which produce it. That the species is 

 constant is not true ; it is not distinguishable by in- 

 variable characters. Species only have a constancy rela- 

 tional to the duration of the circumstances under which 

 the individuals have lived." 



Each of these parts is illustrated with maps showing 

 the localities of the forms described, and with carefully- 

 drawn figures of the plants themselves and of the 

 flowers. 



Blue Marking Ink. — Mbc a sufficient quantity 01 ultra- 

 marine with barytes (sulphate of barium, Wane fix) and 

 water to produce the desired tint. It may be rendered more 

 permanent by adding some liquid glue (solution of glue in 

 acetic acid) or some starch paste, prepared with the addition 

 of a little wax. — Chemist and Druggist. 



