LITERARY NOTICES. 



703 



An Introduction to Entomology. By John 

 Henry Comstock. With many Original 

 Illustrations, drawn and engraved by An- 

 na BoTSFORD Comstock. Part I. Ithaca, 

 N. Y. : The Author. Price, $2. 

 Prof. Comstock designs that this work 

 shall enable students to acquire a thorough 

 knowledge of the elementary principles of 

 entomology, and to classify insects by means 

 of analytical keys similar to those used in 

 botany. As the completion of the work has 

 been delayed by other duties, the author has 

 thought best to issue this part by itself. 

 The first three chapters are of an introduc- 

 tory character. In Chapter I the general 

 characters and metamorphoses of insects, 

 which term the author restricts to the Hexa- 

 poda, are stated ; Chapter II is a description 

 of the anatomy of insects, fully illustrated ; 

 and Chapter III is devoted to the classifica- 

 tion of the Hexapoda, The remaining chap- 

 ters consist of descriptions of the more com- 

 mon or conspicuous species in each family, 

 together with keys by means of which the 

 student can readily determine to what family 

 any insect of which he has a specimen be- 

 longs. In many cases tables of genera are 

 also given. Much space has been devoted to 

 accounts of the habits and transformations 

 of the forms described. The needs of agri- 

 cultural students especially having been kept 

 in view, those species that are of economic 

 importance have been described with consid- 

 erable fullness. The rest of the work will 

 be published as soon as practicable. In ad- 

 dition to the systematic part, in which four 

 more orders — Lepidoptera, Diptera, Coleop- 

 tera, and Hymenoptera — remain to be de- 

 scribed, there are to be chapters on the 

 means of destroying insects or of preventing 

 their ravages, on the collection and preserva- 

 tion of entomological specimens, on entomo- 

 logical supplies, a classified list of entomo- 

 logical works, a glossary, and an introductory 

 chapter. This part comes in paper covers. 

 It is well printed, and is abundantly illus- 

 trated. 



Gleanings in Science : A Series of Popular 

 Lectures on Scientific Subjects. By Ger- 

 ald MoLLOY, D. D., D. Sc. London and 

 New York : Macmillan & Co. Pp. 352. 

 Price, $2.25. 



With one exception, the lectures which 

 make up this attractive volume were deliv- 

 ered before the Royal Dublin Society. In 



preparing them for publication the author 

 has used whatever materials have come into 

 existence since the lectures were delivered, 

 so as to present the latest available infor- 

 mation in each case. The subjects treated 

 are included in the sciences of heat and elec- 

 tricity, except the Alpine glaciers, which are 

 described in a lecture delivered to a young 

 men's society. There are two lectures on 

 the modern theory of heat as illustrated by 

 the phenomena of latent heat, one of these 

 dealing with the latent heat of liquids, the 

 other with the latent heat of vapors. Light- 

 ning and thunder are treated in one lecture, 

 lightning-conductors in another, and the 

 storing of electrical energy in a third, while 

 the recent controversy in England on light- 

 ning-conductors is sketched in an appendix. 

 The electric light is the subject of two lect- 

 ures ; one telling how the electric current is 

 produced, the other how the current is made 

 to yield the light. Two lectures also are de- 

 voted to the sun as a store-house of energy : 

 one describing the immensity of the sun'a 

 energy, the other discussing the theories as 

 to its source. The treatments are thoroughly 

 popular, avoiding mathematics and technical 

 language, and, besides setting forth the pres- 

 ent state of the science in each case, touch 

 upon the history of the subjects and the 

 practical applications of the principles stated. 

 Descriptions of experiments are introduced, 

 which the reader is helped to realize by 

 many excellent illustrations. The lecture 

 on " The Glaciers of the Alps " is especially 

 fascinating, and owes part of its interest to 

 the quotations and cuts borrowed from Mr. 

 Whymper's " Scrambles among the Alps." 

 The whole volume, in manner as well as in 

 matter, reminds one of Tyndall's popular 

 works, and will be found very attractive 

 reading for any one who has an intelligent 

 interest in science. 



The Civilization of Sweden in Heathen 



Times. By Oscar Montelius, Ph. D. 



Translated by Rev. F. II. Woods, B. D. 



London and New York : Macmillan & Co. 



Pp. 214. Price, $4. 



As in most countries, the archaeological 

 chronology of Sweden embraces a stone, a 

 bronze, and an iron age. The stone age is 

 regarded as extending to about 1500 b. c. 

 In his chapter on this period the author de- 

 scribes a considerable variety of tools and 



