REVIEWS 



The Cambridge Natural History. Edited by S. F. Harmer and A. E. Shipley. 

 Vol. IV. Crustacea and Arachnids. By the late Prof. Weldon, 

 Geoffrey Smith, Henry Woods, A. E. Shipley, Cecil Warburton, 

 and Prof. D'Arcy W. Thompson. [Pp. xviii + 566.] (London : Mac- 

 millan & Co., 1909. Price 17^. net). 



The Cambridge Natural History is now completed by the issue of this, the fourth 

 in order of the ten volumes, and the editors are to be congratulated on having 

 brought to a successful conclusion the enterprise begun some sixteen years ago. 

 In several respects the work as a whole occupies an important place in scientific 

 literature ; not least in that it is the only " Natural History " in the English 

 language which, while written for the non-specialist reader, devotes a due propor- 

 tion of space to the invertebrate groups of the Animal Kingdom. 



As in the case of several of its predecessors, the various sections composing 

 the latest volume differ considerably in method of treatment, and do not all reach 

 the same standard of excellence. The longest section is that dealing with the 

 Crustacea, and it has suffered somewhat from the melancholy circumstance which, as 

 explained in the preface, has delayed the appearance of the volume. The Crustacea 

 were to have been dealt with by the late Prof. Weldon, of Oxford ; but at his 

 untimely death only the chapter on the Branchiopoda was left ready for publica- 

 tion, and the remainder of the section has been written, at very short notice, by his 

 pupil, Mr. Geoffrey Smith. Prof. Weldon's chapter provides a very full and lucid 

 account of the group with which it deals. It is illustrated by a large number of 

 exceptionally fine original figures, and the few inaccuracies which may be detected 

 would doubtless have been corrected had the author lived to revise it. As it 

 stands, however, this chapter, extending to thirty-seven pages, is out of proportion 

 to the rest of the section, and this has made it necessary to deal more briefly than 

 was desirable with the other orders of Crustacea. Mr. Smith's contribution bears 

 evidence of having been somewhat hastily compiled, and its various parts are of 

 very unequal value. On some subjects, of which the author has made a special 

 study, he writes in a very interesting fashion ; and the accounts which he gives of 

 the wonderful life-history of the Rhizocephala (p. 95), of the phenomena connected 

 with growth and sex (p. 100), and of the structure and modifications of the eyes 

 (p. 146) are especially well worth reading. Unfortunately, when on less familiar 

 ground, he is here and there betrayed into statements which seem to admit of no 

 other explanation than that said to have been offered, on a certain celebrated 

 occasion, by Dr. Samuel Johnson. In stating that the Stomatopoda have "ten 

 hepatic diverticula given off segmentally from the alimentary canal " (p. 142), Mr. 

 Smith is only repeating a venerable error of the text-books ; and in attributing 

 to Nebalia a brood-pouch like that of the Mysidae (p. 112) he has been misled by 

 the statement of a recent writer ; but he might have hesitated before describing 

 Caligus lacustris as "common in fresh-water lakes and streams" (p. 74), or 

 Carcinus m<z?ias as absent from the Mediterranean (p. 194). Stenochotheres, 

 three times repeated on p. 76 for Stenothocheres, and "retinaculas" on p. 142, may 



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