784 NATURAL SCIENCE. dhc. 



The first chapter is introductory, and shows how man, with all his 

 machinery, is, after all, greatly dependent on natural forces for the 

 oroduction of his crops. Chapter II. brings forward the "pioneer 

 labourers," the gases of the atmosphere, moisture, frost, alternation 

 of heat and cold, wind and rain, glacier and volcano, the great natural 

 forces which split or wear away the fundamental rock. Then come the 

 humbler "soil-makers," the tiny lichen, which, living on the bare rock, 

 helps to break up the surface and by its decay to form a thin film of soil 

 in which mosses can root, to be ultimately followed by dwarf shrubs. 

 But the soil to be really productive must be mixed ; any one rock 

 will not supply the necessary ingredients in fitting proportions. This 

 leads to the consideration of the soil-carriers, the river and the wind, 

 and we are made to feel the truth of the old proverb that "a peck of 

 March dust is worth a king's ransom." The use of the bind-weed and 

 its relatives, the salt-worts, the mangrove, and other soil-binders is duly 

 explained ; and then follow two most interesting chapters on the " field- 

 labourers," the burrowing mammals, earth-worms, burying beetles, 

 termites, ants, and ant-eaters. 



However rich and well prepared the soil, the plant cannot get on 

 without water, and Chapter VIII. deals with its absorption, retention 

 — especially by desert plants — and transpiration. This leads to 

 " deserts," those regions where the soil may or may not be poor, but 

 Avliere water is scarce, and which are hence comparatively barren. 

 The relation between want of water and scarcity of vegetation, especially 

 of trees, is brought out, and stress is laid on the frequency of drought 

 as a result of ruthless demolition of forests. Roots and food from the 

 soil, leaves and their work, followed by a short chapter on climate, 

 blossom and seed, and the development of the second from the first, 

 the working of Nature's golden rule for flowers — " cross fertilisa- 

 tion " wherever possible, guests welcome and unwelcome, and the 

 scattering and carrying of seeds, are subjects of successive chapters. 

 The " Chances of Life " gives a graphic account of the keen struggle 

 for existence, and some of its causes, in the vegetable kingdom. 

 Under " Friends and Foes " the relation between animals and plants 

 is aptly described, the foe of the individual being often the friend of 

 the race. "Nature's Militia" is just now more, appropriate than 

 ever when the plague of field-mice in the South of Scotland has been 

 evoking so widespread an interest. The last chapter — " Man's \\'ork 

 on the Farm" — includes a brief historical summary of the changes in 

 vegetation which man has, intentionally or otherwise, eff"ected by his 

 migrations and taste for cultivation. 



The work as a whole is so good and so admirably put together 

 that one quite regrets to find a slip such as is evidently the statement 

 on p. 162, to the effect that one part in twenty-five thousand is the 

 proportion of carbonic acid gas present in the air ; it should be one 

 in two thousand five hundred, or "04 per cent. It is not correct 

 to say that the leaf of Dioncsa secretes an acid which digests the 

 captured insects, for though the acid may be a necessary accompani- 

 ment, the peptic ferment is the actual digestive agent. In the 

 chapter on " Chances of Life," the authoress, while rightly denounc- 

 ing the popular error of mummy-wheat's germinating, unfortunately 

 adduces, as well-authenticated, the statement that seedlings were raised 

 by Dr. Lindley in Chiswick Gardens from raspberry seeds found in 

 Celtic tumuli, perhaps some two thousand years old, and mentions 

 also as a fact the germination of seeds from Roman tombs. These 

 " facts," however, have never borne the light of investigation, and 



