September 19, 19 12] 



NATURE 



67 



IS introduced into the blood-stream a very serious 

 train of symptoms results which may terminate 

 fatally. Healthy blood contains no enzymes 

 capable of splitting peptone into its simpler and 

 more harmless constituents. But by educating an 

 animal by gradually introducing successively in- 

 creasing doses of the poison, the blood acquires 

 the property of dealing with it, owing to the 

 genesis of peptolytic enzymes. This is only one 

 example of the sort of thing which is continually 

 occurring ; many others are given, which the 

 reader must discover for himself. The little book 

 is valuable also because it deals clearly with the 

 methods, especially the so-called "optical method," 

 which have been elaborated by the author for the 

 detection of the enzymes in question. 



(2) The parathyroid glands were only discovered 

 in 1880, and their importance in the life of the 

 organism was not recognised until some years 

 later. Removal of the thyroid body produces 

 results analogous to those which occur when this 

 organ is the seat of disease. Now that its neigh- 

 bours, the parathyroids, have been recognised, 

 much controversy has centred around the question 

 as to how much of the effect is due to removal or 

 disease of the latter bodies rather than of the 

 thyroid itself. Much difference of opinion still 

 prevails, but it is pretty generally admitted that 

 what is known as tetany is a symptom rather of 

 parathyroid than thyroid insufficiency. The main 

 facts and views are set out with admirable lucidity 

 in the second book mentioned above, and Dr. Louis 

 Morel, the author, is to be congratulated, not only 

 on having written such an interesting book, but 

 on having added to it a valuable bibliography of 

 the subject. This extends over nearly twenty 

 closely printed pages in double columns, and 

 seeing the recent date of our knowledge even of 

 the existence of these little organs, we have an 

 illustration of the industry of modern physiological 

 and pathological investigators. 



(3) The next monograph on our list is published 

 in the same series, which is being published under 

 the editorship of Prof. Dastre. In it, Dr. des 

 Bancels gives the most up-to-date information 

 regarding the two special senses, taste and smell. 



(4) Dr. Cathcart's contribution to the bio- 

 chemical monographs which Messrs. Longmans 

 are publishing deals with the important subject of 

 protein metabolism. This also is enriched with 

 an excellent bibliography. Although one must 

 admire the way in which the author has placed 

 before his readers all the latest information on 

 the complex problems involved, one is naturally 

 disappointed to find how many of these still con- 

 tinue in an uncertain state. That, however, is not 

 Dr. Cathcart's fault, and we must rejoice that he 



NO. 2238, VOL. 90] 



has himself done so much in the way of research 

 to illuminate the dark places of scientific know- 

 ledge. It can only be a question of time and 

 hard work before our difficulties in the interpreta- 

 tion of facts will disappear. W. D. H. 



OUR BOOKSHELF. 



Die Radiumkrankhcit tierischer Keimzellen. Ein 

 Beitrag zur experimentellen Zeugungs- und 

 Vererbungslehre, by O. Hertwig. Pp. iii + i64 + 

 Taf. i-vi. (Bonn: F. Cohen, 191 1.) Price 

 8 marks. 

 The author has planned and carried out a com- 

 prehensive series of experiments with a view to 

 ascertain the effect of exposing to radium the 

 ova and spermatozoa of animals, and of exposing 

 the normal embryo in various stages of its 

 development. 



The axolotl and the frog [Rana fusca) were 

 used in the experiments. The results show that 

 exposure to radium leads, at every stage, to im- 

 perfect development of the embryo ; numerous 

 illustrations (in the text and in six special plates) 

 show that inhibition of development and abnormal 

 development are readily produced. 



The book is divided into three parts ; the first 

 and second parts deal with experiments on am- 

 phibian ova and embryos ; the third part with those 

 of echinoderms. 



The first part describes the results of irradiating 

 fertilised ova at the beginning of segmentation, 

 and the male reproductive cells before fertilisa- 

 tion. The second part describes the changes fol- 

 lowing exposure of the normal embryo at the 

 several characteristic stages, such as the gastrula 

 stage, the development of the nerve-plate, and of 

 the spinal cord. 



A number of microscopical sections are in- 

 cluded in the illustrations to show the far-reaching 

 nature of the changes produced by exposure to 

 the rays of radium. 



Antropologia Generale. Lesioni suW Uomo 



secondo la Teoria dell'Evoluzione. By Prof. 



Enrico Morselli. 671 figs. + 1 plate +3 maps. 



(Turin : Unione Tipografica, Editrice Torinese, 



1901-1911.) 

 From 1887 until 1908 Prof. Morselli, who is 

 by profession a physician, devoting himself 

 to the study and cure of mental diseases, has 

 been in the habit of delivering free courses of 

 lectures on anthropology. The lectures, which 

 have been in the course of publication, by instal- 

 ments, for a number of years past, have now 

 been completed, and form a work which represents 

 a monument of patient and painstaking industry. 

 In its conception and execution this work resembles 

 the treatises which are so often produced by men 

 attached to German universities. 



Prof. Morselli 's personality is never obtrusive : 

 he seeks to express the facts as seen and rendered 

 by others; he keeps his own opinions in the back- 

 ground. In the preface he acknowledges his in- 

 debtedness to Haeckel. " Antropologia Generale," 



