REVIEWS. 47 



There are 50 coloured plates, mainly the work of native talent, and 

 no less than 440 text figures, many of them composite, showing the 

 various metamorphic stages of the life-histories. There are of course 

 chapters on General Structure of Insects, Classification and Nomen- 

 clature, and Metamorphosis. But probably the reader will be more 

 interested in the chapters which give large selections of facts from the 

 Indian fauna bearing on the more modern aspects of Entomology, the 

 Means of Defence in Insects, Communication amongst Insects, Tro- 

 pisms (response to stimulus of light, temperature, gravity, air, etc.), 

 Insects and Plants, Symbiosis and Parasitism, and the Balance of Life. 

 Several further chapters treat in detail with the subject of Insect Pests, 

 Control of such Pests both of the Growing Crops and of Stored 

 Products. A chapter on Household Pests naturally leads to others on 

 Insects and Disease, Beneficial and Useful Insects. Probably Avhat is 

 unusual in a book on Entomology is to find a chapter on Some other 

 Animals, which deals with enemies of crops in all classes of animals, 

 from the elephant to the snake, and even the fish. The last half of 

 the volume, the more profusely illustrated portion, deals with the 

 insects of all orders of commoner occurrence and whose control is of 

 more or less importance to the agriculturist. Although written pri- 

 marily for residents in India, there is much in the volume which 

 should ensure a wider circulation, and we congratulate the author on 

 the all-round excellence, not only in the method of presentation and on 

 the value of the matter selected, but also for the illustration and general 

 mechanical get-up. — H.J.T. 



The Genitalia of the Geometeid^^ of the British Isi-es, by F. 

 N. Pierce, F.E.S. (110 pp., 48 plates, with 450 figs.). Price lOs., post 

 free, from the author. — [Concluded.] The term " Furca " has been 

 previously applied to the structure formed by the fusion of the two 

 extensions from the base of the valva, and called the " Sacculi " by 

 Mr. Pierce. In the Transactions of the Entoinelof/ical Society of London 

 for 1910, ]\Ir. G. T. Bethune-Baker published a " Revision of the 

 African species of the Lijcaenestiies group of the Lycaenidae." On page 

 6, in a key to a figure for the description of Genitalia, we read " e. 

 Furca; consisting of two arms from a common base in the harpagones, 

 the support to the penis." There are ten plates of figures of ancillary 

 appendages attached to this paper, many of which show very plainly 

 a structure similar to that of Jinnomos aittnmnaria given in plate iv. 

 Hence, although Mr. Bethune-Baker did not name the processes 

 (Sacculi of Pierce), he named the structure formed by their anasto- 

 mosis as the "Furca." Possibly, since he, Mr. Bethune-Baker, had 

 up to that time largely confined his investigations to the Lycaenidae, 

 he was not aware that in the Geometers the Furca was represented by 

 two quite separate processes. Hence Mr. Bethune-Baker is the author 

 of the term "Furca," June, 1910. 



The consideration of these two papers and the careful examination 

 of the plates of figures of genitalia there given, brings us to another 

 point, which was strongly suggested by the study of the above-men- 

 tioned slides and numerous slides of profiles, and that is that diagram- 

 matic figures are not sufficient, and especially if those figures be of 

 the structures " cut " and "spread." By all means let us have the 

 diagrams, but only as an elucidation of the photographs. Granted 

 that the photograph gives too much or not enough, these defects can 



