REVIEWS 521 



would expect from their wide distribution and striking appearance. The majority 

 of the naturalists who have concerned themselves with this group have confined 

 their attentions mainly, if not entirely, to the systematics. The present book 

 would be useful if it only called attention to this neglected side of the Odonata. 

 It does more than this, however, and provides a very full account of the group 

 from all points of view, and will furnish a much-needed general description of the 

 structure, physiology and life-history of a more or less typical insect that can be 

 used by students. Its utility from this point of view is further enhanced by a large 

 number of figures mostly original, a bibliography, glossary, indices, and a chapter 

 on " Collecting, Rearing, and Biological Methods." 



There is, as the author suggests, a distinct " Australian ' flavour ' " about the 

 book, since most of the forms studied by him and referred to in detail are from 

 that country, This is not a drawback, however, as it enables the student in this 

 country, for whose benefit a chapter on British species has been included, to work 

 out afresh, and confirm by comparative methods, the details referred to. 



Perhaps in some ways the weakest part of the book is that dealing with the 

 embryology, and this is owing to no fault of the author's, but to the fact that our 

 knowledge is incomplete. The standard work still remains that by Brandt, on 

 which the author naturally draws fully; but that was published in 1879, since 

 when not only has our knowledge of technique advanced considerably, but also a 

 good deal more is known of the comparative embryology of insects. We feel sure 

 that the group would repay further investigation. Throughout the author has, of 

 course, relied considerably on the work of others, but in most cases it has been 

 verified by his own researches, and even when this has not been done the facts 

 and theories have been handled in a critical manner. 



The book is to be commended, not only because it fills a useful place in the 

 library of the student and general reader, but also for the broad outlook with 

 which the subject is approached, and the lucid way in which it is stated. 



C. H. O'D. 



The Biology of Water works. By R. Kirkpatrick. Economic Series. No. 7. 



[Pp. iv + 58.] (London : Printed by order of the Trustees of the British 



Museum, 191 7. Price is.) 

 This excellent little volume constitutes one of the well-known Economic Series 

 issued by the Trustees of the British Museum. It explains in a lucid and attractive 

 fashion many of the scientific and practical questions associated with water supplies. 

 The methods of collection, storage, and conveyance are explained and the various 

 sources of supply indicated. The descriptions of the fauna and flora associated 

 with water supplies, and their influence upon those supplies, are given in an 

 extremely attractive manner, the plates being particularly good. Filtration and 

 purification are clearly explained. This one of the series will take its place with 

 the rest as a well-written and informative volume. 



Organism and Environment as Illustrated hy the Physiology of Breathing. 

 By J. S. Haldane, M.D., LL.D., F.R.S., Fellow of New College, Oxford. 

 [Pp. xi + 138.] (New Haven : Yale University Press ; London : Humphrey 

 Milford, Oxford University Press, 1917. Price Si. 25 net.) 



The four chapters of this little volume contain the substance of a similar number 

 of public lectures given by J. S. Haldane at the University of Yale in 1916. They 

 were delivered under the Silliman Foundation, and a fuller and more technical 

 series is appearing in a separate book. 



34 



