7 i6 SCIENCE PROGRESS 



Reptiles and Batrachians. By E. G. Boulenger, F.Z.S. [Pp. xiv + 278, with 

 202 illustrations.] (London : J. M. Dent & Sons. Price 16s. net.) 



This book gives an account of the external appearance and habits of a number 

 of the most interesting reptiles and batrachians (the amphibia of most authors). 

 More than two-thirds of the book is devoted to the reptiles and so covers 

 practically the same ground as Ditmar's Reptiles of the World. It is not so 

 full as the latter, but introduces a certain number of new observations. The 

 descriptions are arranged systematically, but little attention is given to the main 

 points in the anatomy or the relationship of the various groups. It is difficult to 

 reconcile the statement on p. 1 1 1 that the largest snake yet recorded, a python, 

 " is just under thirty-three feet in length" with the one on the following page, that 

 the largest boas "may measure thirty-five feet in length." 



The last part of the work deals in the same systematic way with the batrachians. 

 The section dealing with the transformation of the water-living Axolotl into the 

 terrestrial adult Amblystoma, in particular the author's own experiments thereon, 

 makes very interesting reading. A short note on the possible bearing of these 

 experiments on the position of the Urodela with persistent gills would have added 

 to the interest. It is stated on pp. 271 and 272 that Sip/ionops, an apodous 

 batrachian from S. America, does not lay eggs but brings forth young alive ; this, 

 however, is not accurate in as far as 5. a?inulatus is concerned. This species 

 lays eggs in a string which undergo development on or beneath the surface of 

 damp ground. 



The 176 illustrations from photographs by Mr. Berridge, F.Z.S., form a very 

 good series, portraying many of the animals described in the text. 



C. H. O'D. 



Flies in Relation to Disease : Non-Bloodsucking Flies. By G. S. Graham- 

 Smith, M.D. [Pp. xvi + 389, with 32 text figs., 27 plates and 20 charts. 

 Second, revised and enlarged edition.] Cambridge Public Health Series. 

 (Cambridge : at the University Press, 1914. Price 12^. 6d. net.) 



The first edition of this useful work contained a large amount of information, 

 including much that was original, relating to the bionomics and carriage of disease 

 by non-bloodsucking flies, and, in fact, summarised our knowledge of this subject 

 up to the end of 191 2. In the new edition accounts of researches carried out by 

 the author and other workers during the year 19 13 are incorporated, and are pre- 

 sented in the form of an Appendix ; the latter consists of 87 pages and is illustrated 

 by 3 plates and several charts. The new matter is thus distinct and easily acces- 

 sible ; it is, moreover, arranged in the same order as in the preceding chapters, 

 and each subject is provided with a reference to the page on which it was pre- 

 viously mentioned. 



Interesting observations by the author on the measurements of blow-flies are 

 given which show that a considerable degree of variation occurs in regard to the 

 dimensions of the head, thorax, and wings, and as a result of several experiments, 

 three of which are detailed, it is apparent that " the size of the fly depends on the 

 quality and quantity of the food of the larva, and the time during which it feeds." 

 Further information is given regarding the range of the flight of flies, and attention 

 is drawn to recent papers by Froggatt and others on the changed habits of Aus- 

 tralian blow-flies. These show that in different parts of the world different species 

 of flies may be responsible for similar diseases, and that great changes may take 

 place in the habits of certain species within comparatively short periods of time. 



