220 the entomologist's record. 



rudiments " progressing in development at each stage of growth of 

 the organism, while in the latter these structures grow " concealed " 

 until the penultimate stage, the pupal, is reached. 



This chapter is succeeded by a short one on " Some Wing-less 

 Insects," and introduces us to the changes to which some of our too 

 familiar beasties are subject, shewing that the special transformations 

 that each undergoes are necessitated by the very peculiar environments 

 which affect them. The whole Order of Insecta our author divides 

 into 23 Classes, recognising the Dermaptera as distinct from the 

 Orthoptera, the use of the term Neuroptera in a very restricted sense, 

 excluding the mayflies as Ephemeroptera, putting the booklice and 

 their allies as Corrodentia, the fleas as Aphaniptera and retaining the 

 Strepsiptera. 



A long chapter is taken up with the subject, " Growing Insects and 

 their Surroundings," and gives a large number of very well chosen 

 examples of the variety of form displayed by insects during their 

 period of growth, with especial reference to this important question of 

 Environment. 



The last chapter, entitled " The Problems of Transformation," 

 discusses " what light the transformations of insects throw upon the 

 course of the great periods that mark the progress of life on our 

 earth," and summarises what Miall, Dyar, Comstock, Sharp, Silvestri, 

 Handlirsch, Brogniart, Tillyard and others have said on this 

 comprehensive question. 



The whole work is adequately illustrated by a large number of 

 diagrams, and many references to the sources of much of the informa- 

 tion are given, so that the earnest student may further his studies in 

 each section. The volume is well printed and published and we have 

 much pleasure in recommending it to our readers. — Hy.J.T. 



Applied Entomology. — An Introductory Text-book of Insects in 

 their Eelation to Man. By T. H. Fernald, Ph.D., 400 pages, 388 

 text figures. The McGraw-Hill Book Company, New York and 

 London. Price 21s. — This book is published " as a class-room text 

 for an introductory course in the subject, which shall give a general 

 idea of insects, their structure, life-histories and habits, with methods 

 for the control of insect pests in general." In some 60 pages the first 

 four chapters deal concisely with I. Insects and other Animals, II. 

 The External Structure of Insects, III. The Internal Structure, and 

 IV. The Development of Insects, and give sufficient detailed informa- 

 tion to enable the average student to understand the effects of the 

 application of controls for pests, and also to understand the notes on 

 the various orders and families of insects treated of in the main body 

 of the work. Chapter V., " Losses caused by Insects," summarises 

 the Relationship of Insects to Man both directly on his person and 

 indirectly by attacking his crops, and leads naturally to a consideration 

 of controls, briefly describing the methods evolved by nature to retain 

 a balance of its members struggling one with the other for the right to 

 live. The next four chapters contain an important summary of the 

 " Artificial Methods of Control," classifying them under " General 

 Farm Practices," " Stomach Poison Insecticides," " Contact Insect- 

 icides," and " Fumigation Insecticides." 



The bulk of the volume is a consideration of a selection of the 



