March 27, 1902] 



NA TURE 



483 



and other polished surfaces ; claspers are used upon 

 hairy mammals, such as moles and squirrels. A strange 

 part of the business is, that by no means all the young 

 nymphs of a species change into hypopi, and yet that 

 those which do change include both sexes. How little 

 they resemble the form from which they emerge and to 

 which they return is indicated in the opinion entertained 

 by one writer, that the hypopus was a parasite which 

 entered the nymph and ate it up, all but the skin. To 

 accuse it of such ravaging propensities is peculiarly 

 unkind, since it has but a rudimentary mouth and there 

 is little reason to believe that it feeds at all. The inno- 

 cent purpose of the transformation seems to be merely 

 to secure distribution of the species by varied contri- 

 vances for adhesion to moving objects. Acarids them- 

 selves are a slow-moving race. Unaided they can travel 

 neither fast nor far, though a Gamasid can traverse four 

 inches in a minute. On the other hand, they multiply 

 with a fertility so portentous that any measures for dis- 

 persing the surplus population must be welcome in their 

 commonwealth. But guileless as the hypopi are indi- 

 vidually, a heart of stone would be touched at the afflic- 

 tion they cause in mass to the industrious ant. That 

 long-suffering tribe is said to find some twelve or thirteen 

 hundred species of other animals willing to share, or at 

 any rate that are present among, the amenities of its 

 civilised nests. One of these species is the cheese-mite 

 Tyroglyphns wasmanni, and Wasmann, after whom it 

 is named, found that a single ant might be infested by 

 fifty, or a hundred, or a thousand, or even thousands of 

 the hypopi, not feeding upon it, but clogging all its 

 organs, so that it could neither talk with its antennre, nor 

 feed with its mouth, nor walk with its feet, nor clean itself 

 with its combs, till the poor creature, against its will 

 made sordid and useless, would fall into a lethargy 

 and die. 



Mr. Michael has long held a foremost place among 

 acarologists. It may be confidently assumed that his 

 reputation, high as it is, will be advanced by the present 

 volume. Though the Tyroglyphid^ are comparatively 

 simple in structure, his skilfully drawn plates help us to 

 understand much in them that is peculiar and to admire 

 occasional features that are really beautiful. Notwith- 

 standing the necessarily technical and systematic 

 character of the work, so many suggestive and critical 

 comments diversify the recital that it will be studied 

 with pleasure by readers who are quite outside the 

 limited circle of specialists. T. R. R. S. 



OUR BOOK SHELF. 

 The Journal of the Royal Agricultural Society of Eng- 

 land. Vol. Ixii., 1901. Pp. cciv -f 403. (London: 

 J. Murray.) 

 It is greatly to be regretted that the council of the Royal 

 Agricultural Society has decided to publish the Society's 

 journal in future as an annual volume. For fifty years 

 the journal appeared twice in the year, and during the 

 last eleven years it has appeared quarterly. The altera- 

 tion now made is a very serious retrograde step. Not 

 only is the space occupied by original articles and reports 

 reduced to nearly one-half of that previously found in 

 the Quarterly jou/'iidl, but the publication of new 

 matter is now seriously delayed. We have in this country 

 a sad lack of any provision for the publication of im- 

 portant agricultural papers. Besides the weekly agricul- 



NO. 169I, VOL. 65] 



tural newspapers, we have only the journals of our 

 agricultural societies ; these are small annual volumes, 

 with the exception of the XaXe Journal of the Royal Agri- 

 cultural Society. Thisjournal, with a circulation of 10,000 

 copies, has hitherto done something to provide the re- 

 quired means of publication. In it the majority of the 

 reports by Lawes and Gilbert has appeared. Where 

 could such reports be published now ? The question is 

 a very serious one, for it involves the ignorance or in- 

 struction of our agricultural readers ; and an agri- 

 cultural society could do nothing more useful than the 

 regular and systematic publication of all work relating 

 to the improvement of agriculture. The (Quarterly 

 Journal now issued by the Board of Agriculture does 

 not attempt to discharge this function ; it is principally 

 confined to the publication of statistical matter and the 

 results of experiments carried out with funds supplied 

 by the Board. 



The present volume contains much interesting matter. 

 The long paper on English agriculture in the reign of 

 Queen Victoria is full of facts worth recording, though 

 some strange mistakes are made. What, for instance, 

 was the Royal Chemical Society, founded in 1845 through 

 the efforts of Johnston and \'oelcker? The Chemical* 

 Society of London, to which the author probably refers, 

 was, in fact, founded in 1S41. The Society originated in 

 London. At this time Johnston was a lecturer at 

 Durham, and Voelcker was being educated in Germany, 

 and did not join the Society until 1849! There is a 

 very clear and concise statement by Prof J. McFadyean 

 on the evidence at present existing as to the relationship 

 between human and bovine tuberculosis. This is a 

 weighty utterance on a most important subject. The 

 paper on English varieties of hops will be welcomed by 

 hop-growers. The articles are followed by the usual 

 reports of the Society's chemist, botanist and zoologist. 

 The most notable result in the Society's experiments at 

 Woburn is the immense effect produced by a dressing of 

 lime in the barley-field ; this application of lime has in- 

 creased the produce by ammonium salts in one case by 

 more than thirty bushels. An appreciative biography of 

 Sir J. H. Gilbert is contributed by Dr. J. A. Voelcker. 

 ' R. W. 



Selection of Subject in Pictorial Photography. By 



W. E. Tindall, R.B.A. Pp. 83. (London : Iliffe and 



Sons, Ltd., 1901.) 

 M.\NY of us who frequent photographic galleries or 

 exhibitions have often been struck with the fact that, 

 although a great amount of photographic skill has 

 evidently been bestowed on the production of some par- 

 ticular print, yet in spite of this the effect is not at all 

 pleasing to the eye, and the picture is not " a success." 

 In many cases this is due to faulty composition, the 

 photographer not having paid sufficient, if any, attention 

 to the elementary laws governing this branch of the art. 

 In photography, as in painting, there are many funda- 

 mental rules which must be followed to secure a pleasing 

 effect, and the aim of the author of this book is to set 

 out these points for the use of the photographer. 



In a series of very instructive and interesting chapters, 

 attention is directed to the composition of all kinds of 

 subjects with which the photographer is likely to meet, 

 and the difficulties peculiar to each class are described. 



Further, the author does not restrict himself solely to 

 describing the chief points in the composition of any 

 one subject, but he illustrates them by means of paint- 

 ings, drawings and photographs, which add greatly to 

 the force of the text. 



In conclusion, it may be stated that the author has 

 given us a book which should prove of great service to 

 those who require information on composition in pictorial 

 photography, and a useful addition to the photographer's 

 library. 



