SCIENTIFIC LITERATURE. 565 



concerning sun spots, such as Schaeberle's and Oppolzer's, and an account 

 of Duner's and the author's work on sun-spot spectra; a summary of recent 

 progress in prominence photography, etc. ; facts and conclusions concern- 

 ing the corona, based on recent eclipses; an account of Langley's infra-red 

 spectrum investigation, and of the work of De Chatelier, Wilson, Gray, and 

 Scheiner on solar radiation and temperature; and, finally, a most interest- 

 ing supplementary note, already mentioned, on Helium. The size of the 

 volume has been increased by nearly thirty pages, and the number of illus- 

 trations has been raised from eighty -two to one hundred. 



The Sun, in its new form, certainly deserves, and will unquestionably 

 obtain, an even greater circulation than that which it has hitherto enjoyed. 



u Live v natural history is what Prof. Miall* would lead the young 

 naturalist to. While he has no disparagement for systematic zoology, he 

 wishes to revive an interest in the writings of Swammerdam, Reaumur, 

 Lyonnet, and De Geer, and to promote that observation of the structure and 

 habits of living animals which those authors pursued with most profitable 

 results. In so doing, he is only restoring a balance that has been dis- 

 turbed of late years. It is certainly an attractive field into which our au- 

 thor invites the amateur. Who does not love to follow a stream through its 

 alternations of still deeps and rippling shallows, or to stroll along the shore 

 of the ever-moving sea ? Whether one be occupied with sport or science, 

 the movement of the water and the succession of traces of its action upon 

 the land yield no small enhancement of pleasure. Aquatic insects do not 

 form a distinct class. Representatives of eleven orders are described in 

 this book, so that the spice of variety is not wanting in their study. Under 

 the guidance of Prof. Miall one may watch at leisure the swiftly darting 

 whirligig beetle or examine the fine case of instruments of the female gnat 

 (there are no mosquitoes, our author says, in zoology). Other insects classed 

 as aquatic, because they pass their larval and pupal stages in water, are 

 drone flies (the oxen-born bees of the ancients), dragon flies, pond-skaters, 

 tube-making caddis-worms, etc. ; all are air-breathers in the adult form. A 

 phenomenon which profoundly affects the lives of these creatures is the 

 surface film of water. By curious adaptations they take advantage of its 

 tension, while on the other hand some minute creatures find it a death-trap. 

 The reader must not look for a severely logical arrangement in this book. 

 There is an introduction in which the invasion of the waters by insects, 

 the surface film, live natural history, and other topics are discussed philo- 

 sophically. Directions for capturing specimens will be found not among 

 the preliminary matter, but on page 114, and there are biographical notes 

 about the old naturalists where the first extended citations from their re- 

 spective writings occur. In the illustrations sufficient magnifying power 

 has been used to make the organs of the insects readily distinguishable, 

 with the result of giving some of the little creatures a truly formidable ap- 

 pearance. 



* The Natural History of Aquatic Insects. By L. C. Miall, F. R. S. Pp. 395, 12mo. London and 

 New York : Macmillan & Co. Price, Qs. ; $1.75. 



