March 



1918] 



NATURE 



43 



recessive Mendelian character, a conclusion which 

 has a bearing on the question of intermarriage 

 iind the purity of the Jewish race. 



One or two criticisms must be made on an other- 

 wise excellent book. A number of misprints 

 occur, and the author repeats himself occasionally 

 in a way that must affect unpleasantly the atten- 

 tive reader. Some of the quotations are naive and 

 often irrelevant to the main purpose of the book. 

 The whole chapter on the mathematical problems 

 of the Talmud is outside the scope of the book. 

 In general, one must say that the author gives too 

 much, and one often wonders whether he is writ- 

 ing about the Jewish child or the Jewish family. 

 Finally, is it to be taken as a compliment to our 

 French Allies that the author gives most of the 

 "indecent" quotations in French? This prudery 

 is perhaps out of place in a scientific book. But 

 these minor imperfections can, no doubt, easily be 

 remedied, and we hope that this excellent compila- 

 tion will be rendered more perfect in a second 

 edition, which the book richly deserves. 



J. Brodetsky. 



OUR BOOKSHELF. 

 1 he Linacre Lecture on the Law of the Heart. 

 . Given at Cambridge, 191 5. By Prof. E. H. 

 Starling. Pp. 27. (London: Longmans, Green, 

 and Co., 19 18.) Price is. 6d. net. 



In this lecture Prof. Starling has embodied the 

 main results of the researches which he has 

 carried out during the last few years on the work 

 of the heart. The starting point of the investiga- 

 tion was the introduction by Knowlton and Star- 

 ling of the heart-lung preparation by means of 

 which the output and efficiency of the heart could 

 be accurately studied under practically normal 

 conditions. ' By this method the influence of 

 changes in arterial and venous pressure on the 

 output and volume of the heart, its oxygen supply, 

 and its efficiency have been gradually worked out. 

 The evidence obtained from this many-sided re- 

 search has gradually led up to general conclusions 

 of fundamental importance, one of which gives 

 the lecture its title, and states that "the energy 

 of contraction" of cardiac muscle "is a function 

 of the length of the muscle fibre." In fact, the 

 longer the fibres at the beginning of systole, the 

 stronger is the force of the beat. This property 

 of cardiac muscle, which is equally manifested 

 by skeletal muscle, makes clear, for the first time, 

 the real nature of the so-called "reserve power" 

 of the heart. A rise of arterial pressure or an 

 increase in venous inflow produces a greater 

 diastolic volume of the heart — that is to say, an 

 increased length of its fibres ; the heart therefore 

 contracts more forcibly, thereby maintaining its 

 output against a high arterial pressure, or increas- 

 ing its output when the venous inflow becomes 

 larger. 



This principle is not merely of physiol(^ical 

 value, but also of far-reaching importance in patho- 

 logy, and although the author only hints at this 



aspect, it must have an enormous influence on 

 the clinical treatment of many diseases of the 

 heart. 



Plant Materials of Decorative Gardening: The 



Woody Plants. By Prof. W. Trelease. Pp. 



204. (Urbana : Published by the Author, 1917.) 

 Prof. Trelease's object in this little hand- or 

 pocket-book is an attempt to make it possible for 

 a careful observer to learn the generic and usually 

 the specific names of any hardy tree, shrub, or 

 woody climber that may be found cultivated in 

 the eastern LTnited States — excluding the extreme 

 south — or in northern Europe except in the more 

 pretentious estates or botanical establishments. 

 The manual, which is of a convenient size, 

 has been very carefully and thoughtfully com- 

 piled. Some 247 genera and 782 species, with a 

 number of minor forms, are dealt 'with — in all, 

 1 1 50 distinct kinds of plants belonging to eighty- 

 three natural families. The book opens with 

 dichotomous keys to the genera, which have been 

 found to work very well, and are followed under 

 each genus by keys to the species, a description 

 of each genus being given before the keys. In 

 addition to the Latin names, the common names 

 of the plants are also given. 



For the gardens of eastern North America no 

 doubt the keys to the species are ample, but for 

 Great Britain in many cases they are too meagre. 

 Under Cotoneaster, for instance, of the six species 

 mentioned only one, C. microphylla, is commonly 

 found in our gardens, while many familiar species 

 cultivated in this country are omitted. Berberis 

 affords another example, as our gardens are get- 

 ting filled with new introductions from China, of 

 which no mention is made. 



The principle of the manual is good, however, 

 and in such features as it may be lacking we 

 have other books to hand which fill its gaps. 

 One of its chief merits is the vast amount of in- 

 formation it compresses into a small space. 



There is a useful glossary at the end, and also 

 a carefully prepared index. 



Laboratory Glassware Economy. A Practical 

 Manual on the Renovation of Broken Glass 

 Apparatus. By Prof. H. B. Dunnicliff. 

 Pp. x + 92. (London: Macmillan and Co., Ltd., 

 1917.) Price 45. net. 

 To overcome the great difficulty experienced by 

 teachers of practical chemistry in Indian colleges 

 in procuring supplies of glassware during the 

 war, Prof. Dunnicliff devised a number of easy 

 methods of renovating and adapting to new uses 

 damaged apparatus made of glass. In this work- 

 manlike little book he describes the processes he 

 has developed and explains how difficulties may 

 be surmounted with success. Teachers in charge 

 of chemical laboratories at home will find the 

 volume very useful, and the uses for damaged 

 calcium chloride tubes, broken test-tubes, flasks, 

 retorts, burettes, and so on, will show them how 

 they may both effect economy and maintain 

 efficiency. 



NO. 2^2 



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