SCIENCE- GOS SIP. 



i|[ 



be conveyed to other inland waters, where it would 

 again repeat its victorious march. 



It is in consequence of this survival of the 

 organism best suited to the conditions in which it- 

 is placed that new varieties, species, genera, families, 

 and orders have gradually arisen. One cannot lay 

 too much stress upon the slow and gradual nature 

 of this process. The variation that gives the first 

 advantage to any individual may be so trivial as to 

 be practically unrecognisable to the human mind ; 

 but so keen is the ceaseless combat of organism 

 against organism that even this minute divergence 

 from the ordinary will tell in the course of years. 

 •One finds it hard to conceive the space of time that 

 must have elapsed to produce those broad differ- 

 •ences in character which we recognise as of specific 

 •value ; and when we further consider genetic and 

 ■ordinal dissimilarities, our short quantum of years 

 gives us no measure with which to span the ages 

 that must have passed. 



There are some physicists who have estimated 

 the age of the earth at, at least, one hundred 

 million years, and this is sufficient to satisfy even 

 the demands of the student of organic evolution. 



Bearing in mind these life-and-death struggles 

 taking place in the lakes and ponds of the ancient 

 earth, we can easily understand the wonderful 

 advantage which any one of the combatant organ- 

 isms would possess if it could adapt itself to a 

 new medium. Supposing among the many creatures 

 that must have been crowded out of the water 

 .altogether, one arose which could continue its life 

 partly or entirely on the dry land ; the possibilities 

 •of development would be immense. It is this 

 very adaptation to amphibious, and later to purely 

 terrestrial, habit which undoubtedly took place in 

 those remote geological times. The great life 

 .struggle was then transferred from the lake to its 

 margins as well. Bit by bit changes took place in 

 the organisms, rendering them more and more 

 independent of the direct proximity of water, and 

 it was these changes which led to the differentia- 

 tion of their internal tissues in all their manifold 

 variety and complexity. 



{To be concluded.') 



Caledonia Evansii new to England. — On 

 October 9th, 1900, beneath a stone in the Wessenden 

 Valley, near Hucldersfield, I captured a tine male of 

 a rare and, up to the present, little-known spider, 

 Caledonia evansii Cb., which has been kindly iden- 

 tified for me by the Kev. O. P. Cambridge. This is, 

 so far as I can discover, its second occurrence only, 

 the solitary genus and species having been founded 

 on specimens taken in the Pentlands by Mr. Evans. 

 The spider would thus seem to be new to England ; 

 but Mr. Cambridge has an idea, though he cannot 

 be certain, as he possesses no record, that it has 

 also been taken in Cumberland. Can any of the 

 numerous readers of Science-Gossip say if this is 

 so or not, and supply the requisite particulars, thus 

 removing any doubt as to its being, as described 

 above, new to England ? — William Falconer, Bank 

 Field, Slaithwaite, Hudders field, September 6th, 1901. 



NOTICES BY JOHN T. CARRINGTON. 



A Text-book of Astronomy. By GEORGE C. 

 Comstock. viii+ 391 pp., 8 in. x 5J in., with 13 

 plates, a protractor, and 150 figures in text. 

 (London : Hirschfeld Bros. New York & London : 

 Appleton & Co. 1901.) 7s. (id. net, 



This is the best text-book on Astronomy for use 

 in schools that has yet come before us. It is one 

 of the Twentieth Century Text-books, edited by 

 Dr. Nightingale, Superintendent of High Schools, 

 Chicago. There is sufficient information contained 

 in its pages to amply found in the scholars, not 

 only a knowledge of astronomy, but also create in 

 most of them a taste for its study in after-life. 

 The letterpress is simply and brightly written, and 

 quite within the reach of any intelligent young 

 person. The work is handsomely illustrated with 

 coloured and plain plates, and also by a series of 

 portraits of eminent astronomers. Altogether, it 

 is a work to be highly recommended. 



Manual of the Birds of Iceland. By Henry H. 

 Slater, M.A., F.Z.S. xxiii + 150 pp., 8 in. x 5 in. 

 Illustrated with frontispiece, 2 plates, and coloured 

 map. (Edinburgh : David Douglas. 1901.) 5s. net. 



The Kev. Mr. Slater, the author of this book, is 

 Eector of Thornhaugh, Northamptonshire, and has 

 for some fifteen years been studying the birds of 

 Iceland. During his various visits to that country 

 he has felt that some popular handbook to its 

 ornithology would be of use to the many English- 

 speaking visitors who go there in increasing 

 numbers. It is evident from the frequent references 

 to other works in various languages that the author 

 has given much attention to his subject. He also 

 corrects errors occurring in literature elsewhere. 

 There is a useful extract from the local laws 

 relating to birds in Iceland, a guide to the pronun- 

 ciation of Icelandic names, and a bibliography. 

 The Latin and English names precede the notes on 

 each species, and are followed by the native names, 

 with explanations of their meanings. This little 

 work will be found useful to the tourist in Iceland, 

 and also to the ornithologist studying the distribu- 

 tion of birds. 



A Civilian War Hospital, By the Professional 

 Staff, xii + 3-43 pp., 8| in. x 6 in. Illustrated. 

 (London : John Murray. 1901.) 12s.net. 



This work constitutes an exceedingly interesting 

 history of the " Portland Hospital," which was 

 equipped through the beneficence of the Duke of Port- 

 land, and. was the first of the civilian hospitals to be 

 sent out to the seat of war in South Africa in 1899. 

 Further, it was probably the first volunteer under- 

 taking of its character that had been attached to 

 a British army on active service. The articles 

 constituting the work before us are contributed by 

 the professional staff, which consisted of Anthony 

 A. Bowlby, C.M.G., F.R.C.S., Senior Surgeon ; 

 Howard H. Tooth, M.D., C.M.G., F.R.C.P.; Cuthbert 

 Wallace, M.B., B.S., F.R.C.S. ; John E. Calverley, 



