NA TUKE 



481 



THURSDAY, JUNE 23, 1910. 



INDIAN ENTOMOLOGY. 



idiau Insect Life; a Manual of the Insects of the 

 Plains {Tropical India). By H. Maxwell-Lefroy, 

 assisted by F. M. Hewlett. Pp. xii + 786. (Calcutta 

 and Simla : Thacker, Spink and Co. ; London : 

 W. Thacker and Co., 1909.) 



rHIS handsome volume reflects great credit upon 

 its authors, who occupy the posts of ento- 

 ologists to the Imperial Department of Agriculture 

 r India; and also upon the staff of the Agricultural 

 esearch Institute at Pusa, under the auspices of 

 hich the observations and specimens have been col- 

 ^cted on which the present work is based. 



In some prefatory remarks Mr. Maxwell-Lefroy 

 forms us that the book is largely a product of his 

 tare time and scanty holidays, adding that "such 



volume has been so much required that he has 

 it that even an imperfect one was better than none." 

 is estimate of his own work is modest — 



It may be,' he says, "that a better volume will be 

 lilt up on this basis, when the study of Indian ento- 

 ology is further advanced. I may also emphasise the 

 ct that where little is said, little is known, and the 

 anks in the book are designedly prominent to empha- 

 ie the enormous scope there is for work. I trust also 

 at the volume may be a real stepping-stone to 

 ■tter things, and may help those who are advancing 

 ir knowledge of the insect life of India." 



»ring in mind the limitations thus indicated by the 

 ithor himself, we cannot but congratulate him and his 

 ■Uaborators on the amount of useful information they 

 ive contrived to embody in their work, and on the 

 re which has evidently been expended on its get-up 

 id general appearance. So sumptuous indeed is the 

 •ok in these latter respects that the title of 

 Manual " seems to be somewhat of a misnomer. 

 A marked feature of the book is its admirable series 

 illustrations. These have mostly been prepared by 

 e artist staff of the Pusa Institute. Both the half- 

 ne blocks and the line engravings show good work- 

 anship ; while the colour-plates, carried out by the 

 Ucutta Phototype Company, '"under very tr)ing 

 matic conditions and for the first time in India," bear 

 •mpariscn with the best of their class. Many of the 

 tists engaged on these illustrations are, we are 

 formed, natives of India, trained in art schools of 

 at country. Their work is highly creditable to all 

 ncerned. 



The plan of the book is simple. It opens with an 

 trcduction of about forty pages, in which are briefly 

 scussed the structural characters of the class Insecta, 

 ith its position in the zoological scale, the instincts 

 id habits of insects, their classification, and the 

 inciples of nomenclature as applied to the group. 

 le methods of identification of specimens and the 

 .isting appliances for the study of entomologn>- in 

 idia are also noticed, and a section is devoted to a 

 •eful exposition of Indian zoogeography. The food 

 id habitat of insects are dealt with in a practical 

 anner, and the introduction closes with a reference 

 XO. 2 12 I, VOL. St^] 



to the beneficial and other activities of insects in rela- 

 tion to man. 



Following the introduction comes a systematic 

 account, profusely illustrated, of each of the nine 

 orders into which for present purposes the authors 

 divide the class of insects. There is, of course, much 

 divergence of opinion, and more of practice, among 

 entomologists on the subject of classification ; and the 

 authors do wisely in warning the student against 

 '■ getting to attach too much importance to any classi- 

 fication systems except as working conventions which 

 have as much regard to truth as circumstances wiU 

 allow." The characteristics of each order, and those 

 of its subdivisions, are carefully given, and the most 

 noteworthy specific forms under each head are more 

 or less fully dealt with, sometimes, especially those 

 of economic importance, in considerable detail. Many 

 valuable observations on habits and life-histories are 

 incorporated in this portion of the work, which covers 

 the ground in as satisfactor}- a manner as could be 

 expected from the limited space at the authors' dis- 

 posal. 



Finally, we have, somewhat after the manner of the 

 excursuses in Scudder's well-known work on the 

 butterflies of the eastern United States, a number of 

 brief treatises of a general kind, dealing with such 

 subjects as cosmopolitan insects, gregarious habits, 

 attraction to light, insects and flowers, migration, 

 deceptive colouring with other means of protection, 

 galls, silk, the size of insects, and insect noises. These 

 essavs, which are interspersed among the systematic 

 sections of the book, include observations many of 

 which are of great interest and value. As an example 

 of a good field observation, which many travellers will 

 he in a position to confirm, we may cite the follow- 

 ing :— 



■■ If one goes into a grass field, intent on observing 

 large grasshoppers, one will suddenly see a brightly 

 coloured insect jump up, fly a little distance and 

 disappear. . . . The eye has followed the bright 

 colours and loses the insect as these disappear with 

 the closing of the wings at the completion of the 

 flight. One's eye is not seeking the cr}ptically-coloured 

 grasshopper, which thus escapes attention, even if 

 one could easily see the motionless insect." 



The modesty of the claims put forward by the 

 authors tends to disarm criticism ; nevertheless, it may 

 perhaps be suggested that some of the topics, 

 especially those dealt with in the introduction, might 

 with advantage have been treated more fully. It is 

 unfortunate, too, that the authors allow themselves 

 to be influenced by the somewhat silly outcry that 

 has been raised in some quarters against bionomic 

 conclusions "drawn from museum specimens." No 

 naturalist ought to undervalue either museum study 

 or field observation. Each is an essential factor in 

 unravelling the problems of evolution, and each has 

 furnished the other with important suggestions for 

 further research. Field work on mimicry, in especial, 

 owes much to the stimulus afforded by the careful 

 studv of material preserved in collections. 



We do not agree (p. 419) that there is much diffi- 

 culty in distinguishing Terias hecahe in all its forms 

 from other species of Terias, nor that the colouring 



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