AprU, '15] 



REVIEWS 



311 



student of medicine and entomology in touch with the discoveries and theories which 

 underlie some of the most important modern work in preventive medicine." This 

 volume is written by entomologists possessing a keen appreciation of the applied or 

 medical aspects of the subject, a viewpoint, we beUeve, essential to the most success- 

 ful prosecution of investigations along this line. 



The first chapter gives a brief historical survey of the early suggestions regarding 

 the transmission of disease by insects. The next contains a somewhat detailed dis- 

 cussion of forms directly poisonous to man, that relating to spiders, ticks and stinging 

 insects being particularly interesting and demonstrating in a convincing manner the 

 errors sometimes characteristic of popular beliefs. About 60 pages are devoted to 

 species parasitic on man, ticks, Hce, mosquitoes and fleas — all represented by one or 

 more important disease-carriers, which latter receive special attention. . 



The dissemination of disease by insects and their aUies — the foundation of medical 

 entomology — is discussed in its various phases in chapters 5-11, a total of about 100 

 pages. The more important disease-carriers are somewhat fully treated in this por- 

 tion of the work; house-flies, fleas, mosquitoes, tsetse flies, and their relations to 

 diseases indicate a portion of the field covered. 



The necessity of identifying noxious forms has been met by tabulations of the 

 characters of dipterous larvae most Ukely to be encountered (p. 136), of flies frequently 

 mistaken for house-flies (p. 145) and of hominoxious arthropods, chapter 12. This 

 feature and the extended and weU selected bibliography add greatly to the value of 

 the volume, especiaUy for the investigator. There is a large series of excellent 

 illustrations. 



The subject is world-wide in appHcation, vital in interest and the authors, by 

 painstaldng study and investigation, have produced a work which must be extremely 

 serviceable to an extended cUental. 



The Apple Maggot, By W. C. O'Kane, New Hampshire Agricultu- 

 ral Experiment Station, Bulletin 171, pp, 1-120, 1914. 



In this large bulletin Professor O'Kane has given us the results of a long and care- 

 ful study of an important pest. It is evident that no pains have been spared to make 

 the investigation thorough, and in consequence a great deal of valuable new data has 

 been obtained. The buUetin is written in a clear, simple, concise style. It is illus- 

 trated by two maps, sixteen photographs, one drawing and several charts of orchards 

 used in the experiments. Most of the photographs are good, but a few are of an 

 inferior character. Considering the comprehensive nature of the work and the value 

 of good figures, one feels that it would have been an improvement if more good illus- 

 trations had been added representing the various stages of the insect, either natural 

 size or both natural size and enlarged. 



The bulletin begins with a good summary of contents. This is followed by an 

 excellent account of the early history, food plants, distribution and destructiveness 

 of the pest in North America. Then comes a discussion of its economic importance 

 in New Hampshire. The remaining eighty-five pages are devoted to an elaborate 

 account of the life history and habits of the insect, natural enemies, control experi- 

 ments and recommendations for control. The last four pages contain a good bib- 

 liography. 



The subject-matter throughout has been well handled and due attention given to 

 each phase, except that it would probably have been better if another paragraph or 

 two had been added giving a more detailed account of the nature of the injury done 

 by the insect and the manner of distinguishing this from the injuries of other apple 

 insects or from the Bitter Pit disease, which is so frequently mistaken by fruitgrowers 

 for it. 



