82 



a leaf. They hibernate within the mines, the infested area being 

 marked by a swelhng. Pupation occurs in the mine in spring, the 

 adult appearing in May. 



JuNGMAxx ( — ). Physiologisch-anatomische Untersuchungen iiber die 

 Einwirkung von Blausaure au£ Pflanzen. [Investigations of a 

 physiological and anatomical Nature on the Effect of Hydrocyanic 

 Acid Gas on Plants.] — Ber. Deutschen hotanischen Ges., xxxiv, 

 p. 84. (Abstract in Wiener landwirtsch. Zig., 1921, no. 94-95.) 



Studies were made of the action under a variety of conditions of 

 different strengths of hydrocyanic acid gas on numerous plants, and 

 the following conclusions were reached. It is better to use strong 

 doses for a short period than weak doses for a longer one. Care must, 

 however, be taken that the quantity of gas is not increased to a point 

 when the pressure becomes so strong as to force it into the plant cells. 

 Fumigation in sunlight or at high temperatures must be avoided. 



Hill (G. F.). Coptotermes raffrayi, Wasraan (Fam. Termitidae) . — 



Proc. Linn. Soc. N.S.W., Syd'ney, xlvi, pt. 2, 1921, pp. 263-267, 

 15 figs. 



Coptotermes raffrayi, Wasm., the validity of which is not generally 

 accepted by recent writers, is redescribed. 



Ferxald (H. T.). Applied Entomology. An Introductory Text-book 

 oJ Insects in their Relations to Man. — New York & London, 

 McGraw-Hill Book Co., Inc., 1921, xiv + 386 pp., 388 figs. Price 

 S3-50 or 21s. 



After deploring the chaotic condition of the teaching of Entomology 

 in the United States, and remarking on the diverse opinions of authori- 

 ties (to which he adds his own) as to subject matter, methods of 

 presentation, or even the line of training, the author offers this work 

 as " a classroom text for an introductory course." 



Four chapters explaining the taxonomic position of insects, their 

 structure and their development are followed by five devoted to their 

 depredations and remedial measures for them, both natural and 

 artificial, insecticides being treated at some length. Then follows an 

 outHne of the relationships of insects. Each of the remaining twenty- 

 three chapters deals with a separate order, including under each an 

 estimate of its economic importance, as well as detailed accounts of 

 the more important pests in the United States, those of more general 

 distribution being treated in large type, and the local or minor species 

 in smaller type. 



The Arachnida are not included, neither are there any references 

 to literature, presumably on account of the elementary nature of the 

 book. The sources, however, of many of the numerous excellent 

 illustrations are given ; those that are not original have been selected 

 from well-known manuals, and this careful selection enhances the 

 value of this up-to-date but not too technical entomological primer. 

 Unfortunately the index does not include the insects that are illustrated 

 but not mentioned in the text. 



