492 SCIENCE PROGRESS 



which we find in the Hchens dinging to the rocks on the mountain, or the 

 similar association between the common ling or heather and the fungus which 

 surrounds its roots and renders life possible in the poor soil of the moors, 

 Prof. Thomson reveals it all to us with a lucidity and freshness which we 

 seldom find in books of this sort. The carnivorous Butterwort and Sundews, 

 quaint plants which have become carnivorous owing to their hunger after 

 nitrogenous food supplies, and which possess digestive processes very similar 

 to our own, bring home to us how a touch of nature makes alllivingcreatureskin. 



The direct cause together with the process of the annual change of the 

 stoat's coat from rufous to white is difficult to explain, as also is the more 

 gradual change spread over periods of years in other carnivores which change 

 their habitats and thereby alter their pelage for protective purposes. This 

 gradual change of coloration is seen in the leopards frequenting the dry 

 hillsides and low bush jungle when they pass into the highlands and forest 

 belts in Africa. It is while living under the latter conditions that cases of 

 melanism only occur. In such cases the pigment is intensified and the hair 

 darkens. Likewise in a certain species of mongoose {Her pastes gracilis), a 

 near relative of the stoat, we get a variation of colour from a dull brown to a 

 brilliant red according to the nature of the soil which it frequents. Why is 

 it that the black tips of the ears of the mountain hare and the stoat's tail 

 never become white in these seasonal changes ? Is senility alone capable of 

 changing black into white ? 



The references to books for those who wish to extend their knowledge of 

 any particular subject are most useful and are likely to be a great help to the 

 student of nature, while the index at the end adds to the general usefulness 

 of this admirable little book. 



R. E. Drake-Brockman. 



Nature all the Year Round. By J. Arthur Thomson, M.A., LL.D. [Pp. 

 viii + 253, with 52 illustrations by Alice M. Davidson.] (London : 

 The Pilgrim Press, 192 1. Price 12s. td. net.) 



All teachers, to whom this book should appeal, will not find themselves so 

 happily situated as to be able to conduct their pupils along nature's by-ways 

 and occupy their Sunday afternoons by training the powers of observation 

 of their young companions in the open fields as we all would desire. But 

 even those less fortunate dwellers in the towns can usually get away now and 

 again for an hour or two in these days of easy, rapid, and cheap means of 

 travel. In most of the larger towns the local museums, which should always be 

 open to the public on Sunday afternoons, will very often, though not from a 

 physical point of view as healthful, be as instructive as a ramble along the 

 hedgerows. The great point which Professor Thomson's book brings out is 

 that every month in the year has its own peculiar mystery to unfold, and these 

 little secrets are as often as not only revealed for a few hours or days at one 

 particular season, and not to be seen at any other time of the year. 



All children have an innate passion for collecting, and it should be the aim 

 of the teacher to direct this passing fancy or craze in the proper channels so 

 as not only to educate their powers of observation but also their imaginations. 

 Children should be taught to appreciate beauty early, for it is this study of 

 the beautiful (and where can it be better found than in nature) that alone can 

 bring joy and contentment into their lives. Organisations such as the Boy 

 Scouts and the Girl Guides could scarcely do better than to make Nature all 

 the Year Round one of their textbooks. Let us, as Professor Thomson says, 

 cultivate the alert, scrutinising, probing habit of mind, and we shall find 

 romance everywhere. 



The peculiar habits of the hornbill during brooding are interesting, and 

 more could be said about this quaint bird ; but one thing might be mentioned, 

 namely, that as soon as the young are hatched (there are one to two eggs 



