264 



NATURE 



[December 29, 1910 



parasites will only have searched one-fiftieth of a cubic 

 millimetre. Now, since this volume is only about 

 1/150,000,000 of the blood in a man's body, it follows 

 that there is a considerable chance that not a single 

 parasite might be detected, although the individual 

 might have 150 million of them in his circulation at 

 the time ! 



Major Ross's preference for the determination of 

 the " spleen-rate " appears justifiable on grounds of 

 expediency, but, although he points out most of the 

 more obvious fallacies to be guarded against in mak- 

 ing such estimations, he scarcely appears to attach 

 sufficient importance to these. For instance, there is 

 very little experience accumulated as to the length of 

 time which some degree of splenic enlargement may 

 persist after recovery, while the splenic enlargement 

 caused by ankylostomiasis, as has recently been 

 pointed out by Darling, would invalidate the tests in 

 certain localities. 



The section dealing with the laws which regulate 

 the number of anophelines in a locality will be fas- 

 cinating reading to all who have some practical know- 

 ledge of these pests, and is full of most suggestive 

 /natter, much of which will doubtless be put to the 

 test by those who have opportunity. The problem of 

 attempting the destruction or limitation of mosquito 

 life, under conditions where extensive breeding places 

 abound, and where the usual measures appear at first 

 sight impracticable, are boldly faced, and those who 

 are satisfied with Major Ross's mathematical demon- 

 strations on such points as the variations of mosquito 

 density due to various causes, the random scatter of 

 mosquitoes from a given point, &c., will find it neces- 

 sary to revise some views which have been and are 

 extensively held on the impossibility of limiting the 

 mosquito population in certain conditions. 



The thoroughness with which the earlier portions 

 of the book have dealt with all branches of the subject 

 greatly adds to the value of the chapter dealing with 

 the selection of the preventive measures to be made 

 in a given instance, since one is able to follow the 

 author in his clear exposition of the manner in which 

 one must study the local conditions in every instance 

 before deciding on the plan of campaign. As he is 

 careful to point out, without such close study of these 

 conditions a scheme might be drawn up which was 

 foredoomed to failure, and large sums of money might 

 uselessly be thrown away. The chapter abounds in 

 valuable practical hints for the guidance of those re- 

 sponsible for the organisation of such campaigns, and 

 it may also be studied with the greatest profit by 

 laymen whose only desire is to know how best they, 

 individually, may avoid infection on proceeding to a 

 malarious country. 



The second half of the book consists of a series of 

 articles by well-known authorities dealing with experi- 

 ences of individual malarial campaigns in many 

 countries, and these afford a number of object-lessons 

 in the application of the principles enunciated in the 

 first half. There are altogether twenty-one contribu- 

 tors to this portion, and the majority are recognised 

 authorities on the subject of malaria in the particular 

 country dealt with. For instance, the campaign 

 NO. 2148, VOL. 85] 



against malaria in Italy is from the pen of Prof. Celli, 

 while that dealing with the most successful of all 

 malarial campaigns, that in the Isthmus of Panama, 

 has been written by Colonel Gorgas. Dr. Schilling 

 deals with malaria in German possessions ; and the 

 measures employed in French territory are described 

 by Dr. Edmond Sergent. The completeness of this 

 portion of the book is indicated by the fact that it 

 concludes with two most interesting articles on the 

 prevention of malaria in troops in war and in peace, the 

 former by Lieut. -Colonel C. H. Melville, and the 

 .latter by Major C. E. P. Fowler, who was associated 

 with Major Ross in his campaign in Mauritius, to 

 which so many allusions are made in the systematic ' 

 portion. 



Major Ross and his collaborators may be congratu- 

 lated on having produced a work which will be of the 

 highest value to all who are concerned with the future 

 progress and welfare of our tropical possessions. 



W. B. L. 



THE BRITISH MUSEUM COLLECTION OF 

 FOSSIL REPTILES. 

 (i) A Descriptive Catalogue of the Marine Reptiles of 

 the Oxford Clay, based on the Leeds Collection in 

 the British Museum {Natural History), London. 

 Part i. By Dr. C. W. Andrews, F.R.S. Pp. 

 xxiii + 205+x plates. (London : Printed by order of 

 the Trustees of the British Museum, 1910. Sold by 

 Longmans and Co., B. Quaritch, and Dulau and 

 Co., Ltd.) Price 25s. 

 (2) A Guide to the Fossil Reptiles, Amphibians, and 

 Fishes in the Department of Geology and Palaeon- 

 tology in the British Museum {Natural History). 

 Ninth edition. Pp. xviii+iio. (London: Printed 

 by order of the Trustees of the British Museum, 

 1910.) Price gd. 

 (i) 'T^HE museum having acquired the unrivalled col- 

 J- lection of reptilian remains obtained with 

 much labour and unceasing care by the Messrs. Leeds 

 —more especially Mr. A. N. Leeds— from the brick- 

 pits in the Oxford Clay near Peterborough, it was 

 only fitting that they should be described in a manner 

 worthy of their importance and value. So far as the 

 marine forms are concerned, that is to say, the ich- 

 thyosaurs, plesiosaurs and pllosaurs, and crocodiles, 

 the task has been entrusted to Dr. C. W. Andrews, 

 who for several years past has devoted a large portion 

 of his time to the study of the^se groups. How 

 thoroughly well he has accomplished the work will be 

 apparent to all specialists who study the present 

 volume, which deals with the ichthyosaurs and plesio- 

 saurs. 



The work appeals, however, to other than special- 

 ists, for it not only serves to make known the remark- 

 ably fine state of preservation in which many of the 

 skeletons of these strange reptiles are found, but it 

 also contains a number of interesting observations 

 with regard to their probable mode of life and the 

 conditions in which they existed. So nearly complete, 

 indeed, are many of the skeletons, that not only has it 

 been found possible to mount several for public exhibi- 



