DISCOVERY 



329 



ceeded in his task — that of writing not so much a textbook 

 of elementary Zoology as a textbook of elementary Mor- 

 phology — we must confess to a feeling of disappointment. 

 Professor Kerr says that " one of the first endeavours of 

 a teacher of Zoology should be to cast over the minds of 

 his pupils some of the fascination of the most fascinating 

 of sciences," but it may be doubted whether this book 

 will attract many students to its subject. There is a 

 failure to knit the animal kingdom together, to direct 

 attention to the different origins of analogous organs — 

 of the body cavity, for instance —to follow the varying 

 fates of homologous organs in different groups. It pro- 

 vides a clear description of the morphological details of 

 nearly all groups, but it is a dry description rather in 

 the nature of a general taxonomic account of the animal 

 kingdom. There is no attempt to spare the student the 

 learning of those innumerable technical terms which cumber 

 zoological literature. Why should not the " branchio- 

 stegite " of the crayfish, for instance, be called just what 

 it is, namely, the gill cover ? The only remarkable 

 feature of the book is the space devoted to parasites ; a 

 large amount of space under this heading is given which 

 will be useful to medical students as it is not easily found 

 elsewhere under one cover. 



Turning to points in detail, it is unfortunate that the 

 term " nephridial organs of Vertebrates " should be 

 retained. The use of this phrase tends to obscure the 

 essential fact that these organs are coclomoducts. The 

 very definite statement on p. 295 (though qualified on the 

 following page) about bony tissue in the dogfish is mis- 

 leading. 



A. M. C.-S. 



An Introduction to the Theory of Relativity. By L. 



Bolton. (Methuen & Co., Ltd., 5s.) 

 Relativity and Gravitation. Edited by J. Malcolm 

 Bird. (Methuen & Co., Ltd., 8s. bd.) 



So many books of a popular nature have now appeared 

 on the theory of relativity that surely the only outstanding 

 difficulty of the subject must be that of finding suitable 

 titles for them ! These two books, however, are out of 

 the ordinary. The first is by Mr. Bolton, the lucky man 

 who won the prize of ;^i,ooo offered by the Scientific 

 American for the best account of the theory in less than 

 three thousand and one words. It is an expansion of the 

 winning essay to twelve times its length. The author has 

 not hesitated to use a little elementary mathematics in 

 the discussion. 



The second contains Mr. Bolton's essay in its original 

 form and selections from some of the essays which 

 came near to winning the prize. The sub-editing and 

 piecing together of these so as to describe important parts 

 of the theory in detail has been done by an associate editor 

 of the Scientific American, and done rather well. A list 

 of those "honourably mentioned " is given. Two inter- 

 esting questions arise. One is, " Why is it that the 

 many distinguished Professors of Physics and Astronomy, 

 who competed, allowed themselves to be beaten by one 

 who holds no position at a University? " and the other, 

 " Whj- is it that several, who are known to have competed 



and vet who were not honourably mentioned, still persist 

 in writing about the subject ? 



A. S. R. 



.itnong the Hill-folk of Algeria. By M. W. Hilton- 

 Simpson, B.Sc, F.R.G.S., F.Z.S., F.R.A.L (Fisher 

 Unwin, Ltd. Illustrations and Map. 21s.) 



The Berber tribes of Algeria have always held strong 

 claims to a romantic interest as a fair-haired, blue-eyed, 

 physically " European " type in an Oriental setting, and 

 to an ethnological interest as a survival of the indigenous 

 population of North Africa which has remained racially 

 uncontaminated by the great Oriental invasion that flowed 

 round and past their mountain strongholds seven centuries 

 ago. 



Their position is not unlike that of the Basques on the 

 eastern slopes of the Pyrenees, that ancient race which 

 was itself untouched by the Aryan tide, and some slight 

 affinity of language has lent colour to the theory that both 

 Basques and Berbers are survivors of the original inhabit- 

 ants of the great European continent before the Straits of 

 Gibraltar divided it from .\frica, cutting off the Berbers, 

 together with that other interesting survival, the Barbary 

 stag, from their Northern relatives. 



The interest is greatly enhanced by Captain Hilton- 

 Simpson's discovery of many hitherto undescribed 

 customs and beliefs in the Berber tribe that he studied. 

 The present book is the firstfruits of three winters spent 

 by the author and his wife among the hill-folk of the 

 Aures Mountains, only thirty miles from the tourist-town 

 of Biskra, yet so remote in their cliff dwellings and almost 

 inaccessible ravines that in many villages the female 

 inhabitants had never seen a European woman. 



The chief object of the expedition was to collect native 

 implements and handiwork, and if possible to investigate 

 the primitive native surgery and bring back specimens of 

 the surgical instruments used. This promised to be a 

 matter of considerable difficulty, for, as the unqualified 

 practitioners are discouraged by the French officials and 

 held answerable at law for their failures, their very exten- 

 sive practice is carried out in secret ; but the author, after 

 gaining the confidence of the people by his interest in 

 hunting and by generous dispensations from his medicine 

 chest, was able to obtain first-hand evidence, finally even to 

 be adopted as a pupil, and he was rewarded by being able 

 to observe the medicine and surgery of Mediaeval Europe 

 in actual application. 



Trephining the skull seems to be the chief major opera- 

 tion (amputations being forbidden by the Mohammedan 

 religion) and principally employed, rationally though 

 sometimes unnecessarily, for the head injuries common 

 enough in a turbulent race of mountaineers. There is no 

 record that the operation is ever performed " to let out the 

 evil spirit " as used to be done apparently in the South 

 Sea Islands. The operation is carried out in several stages, 

 for tough as the patients are, only a little drilling and saw- 

 ing can be done each day till a di.sc of bone is free enough 

 to be removed in one case with a screwdriver. Although 

 neither anaesthetics nor antiseptics are used, a fair 

 number of successful results seem to be obtained. Both 



