90 TAprii, 



in the ordinary metamorphosis when no provision seems to he made for ordinary 

 respiration. The decrease of the lethal period with increasing temperature is 

 also explicable on the enzymic supposition. The fact that the insects are more 

 quickly killed when the gas is lighter or less dense is probably to be explained 

 by the laws of gaseous diffusion: the gases produced by the "internal" respira- 

 tion (i.e., breaking down of reserves) would be more rapidly diffused in a 

 lighter atmosphei-e, and hence the using up of the reserve sxibstances would be 

 accelerated. 



From a practical point of view, the writers are forced to the conclusion 

 that these inert gases cannot be economically used as asphyxiating agents, 

 owing to the capacity of the grain-pests for remaining alive so long in an inert 

 state ; also, in the case of carbon dioxide, the gas injures the germinating 

 power of the grain. Resort must therefore be had to active chemical deterrents 

 or mechanical methods of treatment. Chap, vi deals with remedial measures. 



One other point may be briefly alluded to — the effects of moistness ami 

 dryness (Chap. v). It must suffice to say that diyness has a marked inhibitory 

 effect on C. oryzae, while A. unduIotKs on the other hand prefers drj'^ conditions, 

 and R. dominica seems very little affected either way. Desiccation, therefore, 

 though effective against C. oryzae, is not so against all the insects attacking 

 stored wheat in the Punjab. 



leuteuj. 



" A Naturalist in Borneo." By the late Robert W. E. Sheliord, M.A., 

 F.L.S., etc. Edited, with a Biographical Introduction, by Professor E. B. 

 Poulton, D.Sc, LL.D., F.R.S., etc. London : T. Fisher Unwin, Ltd. 1916. 



It was common knowledge with the friends of the late Robert Shelford 

 that many of the weary hoiu's of the long and distressing illness preceding 

 his vmtimely death were occupied in pxitting together the numeroiis notes and 

 reminiscences of his seven 3^ears' curatorship (1897-1905) of Rajah Brooke's 

 Museum at Sar.awak, as the basis of a volume dealing witli the Natural History 

 and Entomology of that most interesting region of the great Island of Borneo. 

 Although this material was left in a somewhat unfinished state, its judicious 

 and careful editing by his friend Professor Poulton — at whose suggestion the 

 work was undertaken, and to whom we owe the introductory sketch of the 

 author's career — aided by those well-known Bornean authoi-ities. Dr. C. Hose 

 and Mr. H. N. Ridley, with others, has i-esulted in the handsome volume now 

 before us, replete from cover to cover with first-hand observations on the 

 splendid tropical fauna of Sarawak. Shelford was first of all an Entomologist, 

 though of exceptionally wide knowledge and sympathies in all branches of 

 Natviral Science, and Chaj^ters V to IX, about one-third of the book, are 

 devoted to the insect life of that region. His favoiirite Order, the Orthoptera, 

 is, as might be expected, treated in much detail, and a large amount of informa- 

 tion is given respecting the many striking forms of these insects which came 



