1912] The Ottawa Naturalist. 91 



it describes in very clear language the methods by which the 

 elementary student may familiarize himself with and study the 

 structure, life-history and classification of insects. An excellent 

 key to the different orders is given; in the preparation of this 

 key the authors have been fortunate in securing the helpful 

 criticism of the leading authorities in the various orders, thereby 

 rendering it increasingly valuable and accurate. 



In a book of this nature there are naturally a number of 

 points which, if space did not forbid, we might discuss. It is 

 unfortunate that "oesophagus" should be mis-spelt throughout 

 the book, and surely "axe" does not, even on the ground of 

 simplified spelling, deserve to have the "e" chopped off (p. 337). 

 The so-called "rasp-like" character and "rasping" function of 

 the labial lobes of the house-fly and blow-fly (p. 18) are mistakes 

 which have crept into entomological literature due to an incorrect 

 interpretation of the nature of the pseudotracheae resulting 

 from lack of actual observation and careful examination. The 

 statement that "no true gills, that is, gills carrying blood vessels, 

 like those of fishes, are found in insects," whilst strictly true, 

 might be misleading in view of the possession by larval Chirono- 

 mids of respiratory filaments containing blood spaces and similar 

 in function to the gill filaments of fishes. Among the minor 

 mistakes we notice " Corisidae" (p. 108), "Torie" (p. 305) and 

 the laying of Fig. 434 on its side. We are of the opinion that 

 some mention of such important facts as parthenogenesis and 

 the alternation of generations, etc., would have enhanced the 

 biological side of the book. 



The book is well illustrated with nearly five hundred figures 

 which have been selected with considerable care from good 

 sources, and we note with no regrets the absence of many old 

 acquaintances which have been rightly allowed to enjoy their 

 well-earned rest. To all, whether thev be teachers or students 

 or those merely desiring to learn something about insects, we 

 recommend this book most heartily. 



C. Gordon Hewitt. 



The Flight of Birds. By F. W. Headley, M.B.O.U. With 

 sixteen plates and many text-figures. Witherby & Co. 

 326 High Holborn, London; 163 pp. Price, 5s. net. 



"The Flight of Birds" is the first book which has come to 

 our notice dealing exclusively with the science of flight from an 

 ornithological viewpoint. It is only within recent years that 

 the subject has had much attention from naturalists, and this 

 chiefly by European ornithologists. The subject seems not to 

 have been studied to any extent in a systematic way on our own 

 continent. 



