215 



KECENT LITERATURE. 



Insects, their Structure and Life : a Primer of Entomology. By George 

 H. Carpenter, B. Sc.Lond. 8vo, pp. xii, 404, illustrated. 

 London : J. M. Dent & Co. 1899. 



The literature treating of the subject of entomology has become 

 so extensive that it is hardly possible for the average student to keep 

 himself quite posted up to date. A work therefore whicb, in a com- 

 paratively small compass, gives a comprehensive digest of the latest 

 additions to our knowledge should certainly be accepted as a distinct 

 boon. v 



The author of the volume under notice is to be congratulated on 

 the very able way in which he has dealt with the large amount of 

 material at his command, presenting us with an epitome of the 

 work and teachings of present-day morphologists, biologists, and 

 systematists. The book comprises six chapters, as follows: — 1. The 

 Form of Insects ; 2. The Life-history of Insects ; 3. The Classification 

 of Insects; 4. The Orders of Insects ; 5. Insects and their Surround- 

 ings; 6. The Pedigree of Insects. There is also a very full bibliography 

 and a convenient index. 



The class is divided into fifteen orders, and these are considered as 

 here enumerated : — Collembola, Thysanura, Dermaptera, Orthoptera, 

 Platyptera, Thysanoptera, Hemiptera, Plectoptera, Odonata, Neuro- 

 ptera, Coleoptera, Trichoptera, Lepidoptera, Diptera, Hymeuoptera. 



The relationship of the orders is discussed at some length in 

 chapter 6. 



In discussing the classification of insects (chapter 3) our author 

 remarks (pp. 157-159), under the sub-heading " The Search for a 

 Natural Classification " : — 



" It will have been evident to the reader of this chapter that 

 insect classification is a more or less uncertain thing. The limits 

 which mark off species, genera, families, and even orders, from each 

 other depend largely upon the judgment and opinion of the naturalist. 

 Butterflies and moths may be easily enough distinguished from cock- 

 roaches, but some of them show a remarkable likeness to caddis flies. 

 This difficulty in classification is just what we should expect, if, as we 

 believe is the case, all insects are really related to each other. We are 

 able to draw hard and fast lines between some groups because in the 

 course of ages they have diverged far from their common stock. But 

 the more nearly related insects are, the more difficult do we find it to 

 make them fit into the divisions that we have made for their reception. 

 Could a naturalist have before him all the insects which live or ever 

 have lived on the earth, his divisions would entirely break down, and 

 his system of species, genera, families, and orders would become lost 

 in a well-nigh indefinable gradation of characters. The object of the 

 classifier is so to arrange the insects which he does know that they 

 may fall into their right positions with regard to those vanished races 

 that must once have formed the connecting links between them. The 

 truly natural classification of insects is that which will place them on 

 their right branches of the great tree of animal life. The labours of 

 the classifier are usually presented in the form of lists or catalogues ; 



