3^2 



NA TURE 



[February 8, 1900 



Scharff distinguishes three main lines of migration to 

 these islands — the Siberian, the Arctic (which he care- 

 fully separates), and finally the Oriental. Besides these 

 three trunk routes, so to speak, a considerable quota of 

 our fauna has arrived here from such centres of dis- 

 persal as the Lusitanian area. It is often put forward 

 that the fauna of Europe show more likenesses to that 

 of Africa than to that of Asia — " Oriental " Asia, that is 

 to say. Dr. Scharfif does not omit to notice this view, 

 but will not allow an African origin for any part of our 

 fauna. On the contrary, he is disposed to think that the 

 spreading of animals has been in a exactly opposite 

 direction, and that Africa has been partly peopled from 

 Europe. ' 



We can distinctly commend this book, which is agree- 

 able reading as well as a repertory of important facts. 

 Its value is considerably increased by a short summary 

 at the end of each chapter of the line of argument pur- 

 sued and the results arrived at. Numerous engravings 

 and maps, all of them in the text, add to its usefulness ; 

 while a selected bibliography will enable the non-expert 

 reader to pursue his inquiries further into any particular 

 matter not treated at length in Dr. ScharfTs book. 



F. E. B. 



OUR BOOK SHELF. 

 Le Cidre. Par X. Rocques. Pp. 171. (Paris : Gauthier- 



Villars, 1899.) 

 In a country where the technical difficulties of the wine- 

 grower and the brewer have been considered worthy of 

 the attention of such a man as Pasteur, it is not surprising 

 that the cider-maker should receive help from science. 

 That this is so, is rendered very evident by M. Rocques 

 in the small volume before us, where we find in a con- 

 densed, but very readable form, an account of the valuable 

 aid French men of science are giving to the cider industry. 

 In England we are, of course, behindhand in such a 

 matter, but there is, perhaps, some excuse in this case, as 

 cider has not the economic importance here that it pos- 

 sesses in France. In that country, where the mean 

 annual consumption of cider is twelve million hectolitres, 

 representing one-fifth of the alcoholic beverages con- 

 sumed, economic considerations affecting its production 

 are naturally very great, and the importance of scientific 

 help proportionately large. 



But, according to the author, one point in connection 

 with the cider industry tends to hinder somewhat the 

 adoption of scientific methods by the manufacturers, and 

 this is the remarkable fluctuations in the apple crop com- 

 pared with the fluctuations in the other leading agri- 

 cultural crops of France. The proportion of the minimum 

 wheat crop to the maximum is i to i^, and of wine, i to 

 2 ; but in the case of cider there "is the very great 

 difference of i to Z\. It appears, in fact, on taking the 

 average of the last twenty-five years as a guide, that a 

 good apple crop can only be expected one year in two. 

 Such uncertainty in the crop, no doubt, tends to hinder 

 rapid progress in the art of cider-making ; but, on the 

 other hand, progress is assisted by the growing custom of 

 establishing well equipped breweries, which are supplied 

 with apples from the smaller growers who previously made 

 their own cider on a small scale with poor appliances, and 

 in the old rule of thumb style. 



About 40 per cent, of the total production of cider in 

 France is now made in these breweries, much to the 

 comfort and advantage of the consumer, who is not pro- 

 vided by nature with a stomach equal to the action of the 

 acid liquid so often produced by the small farmer. 

 NO. 1580, VOL. 61] 



In the cider breweries working on a sufficiently large 

 scale to permit the adoption of suitable plant and skilled 

 supervision, scientific methods appear to be adopted 

 freely. The diff"usion method, employed so largely in the 

 beet-sugar industry, is utilised for the extraction of apple- 

 juice for the production of certain classes of cider, but the 

 old method of extraction by pressure is still found de- 

 sirable for full-flavoured, sweet ciders, the diffusion 

 process producing a beverage of a drier character. 



Hansen's well-known researches on the pure culture 

 and selection of yeasts, which influence so largely the 

 zymo-technical processes of to-day, are also made use of 

 by the advanced cider-maker for the purpose of im- 

 proving his produce. A composite yeast of the well- 

 known organism, Saccharomyces apicula/us, together 

 with another selected yeast derived from the apple, S, 

 Mali, is found to give good results. As apple-juice, un- 

 like a beer wort, cannot be sterilised by heat in order to 

 provide a clear field for the development of a selected 

 yeast culture, the plan adopted is to nurse the selected 

 yeast growth to such a vigorous state that when used it is 

 capable of crowding out the undesirable saccharomyces 

 naturally present in the apple-juice. 



For the purpose of improving and increasing the flavour 

 of cider, an interesting use is also made of Jacquemin's 

 researches, by which he showed that various parts of 

 certain plants, including the apple, contain glucosides 

 capable of being split up by fermentative action into 

 sugar, and principles possessing the characteristic bouquet 

 of the fruit used. 



We recommend M. Rocques' little volume to all in- 

 terested in technical cider-making, and also to those 

 interested generally in zymo-technical literature. 



A. J. B. 



Liverpool School of Tropical Diseases. Memoir L 

 " Instructions for the Prevention of Malarial Fever." 

 (Liverpool : University Press, 1900.) 



This booklet is the first of a series of memoirs to be 

 issued by the Liverpool School of Tropical Medicine, 

 and is the outcome of the malaria expedition sent out 

 by that body to Sierra Leone. It deals with measures 

 of prevention suggested by observations made on the 

 spot in a malarious country and with the light of modern 

 theory as to the cause of the disease. There are two 

 drawings of the innocent and noxious mosquito which 

 cannot help but impress the imagination of the reader. 

 The idea of alertness and viciousness suggested by the 

 attitude of the latter should make the most careless 

 observer interested in noting which genus of mosquito 

 it is that infects his neighbourhood. 



The memoir, which is clearly and concisely written, 

 contains most valuable information for any one living 

 in the tropics. It is artistically got up, and reflects 

 credit on the school and on the University Press of 

 Liverpool, of which it is one of the first productions. 



Our Insect Friends and Foes : how to Collect, Preserve 

 and Study them. By Belle S. Cragin, A.M. Pp. vi + 

 yj"]. With 255 illustrations. (New York and London : 

 G. P. Putnam's Sons, Knickerbocker Press, 1899.) 

 The title of the work is likely to give the impression 

 that it is devoted to economic entomology, whereas it is 

 professedly a text-book on general entomology and 

 " relations of insects," spiders, scorpions, &c., dealing 

 with the common species of all orders found in "the 

 States east of the Rocky Mountains and north of the 

 Gulf States," including useful instructions on collecting, 

 rearing and preserving insects, their anatomy, &c. The 

 book is written almost expressly for young people, who 

 will find it interesting and instructive in many ways. 

 Unfortunately, many of the illustrations are very poor 

 indeed, and this particularly applies to the Hymenoptera. 



