1908. Rcvietvs, 143 



volume ; 80 pages are devoted to essays ou points in the general 

 bionomics of the Lepidoptera, while in the remaining 400 odd pages we 

 have a detailed systematic account of seven species— the five British 

 " Hairstreaks," and two of the " Blues." 



In the first chapter Mr. Tutt deals with the aestivation and hiberna- 

 tion of the larvae of butterflies. More than half of the British species pass 

 the winter as caterpillars, and besides these " some, possibl}- all, of the 

 butterflies known to us to h} bernate in the ^^^^ stages, really do so as fully- 

 formed larvae, but within not without, the egg-shell." This statement is 

 justified by a reference to our large " fritillaries." Argynnis adippc hibernates 

 in the ^%^. In A. aglaia and Dryas faphia, though "the larvae hatch in 

 July or August, when there is an abundance of food and a high tem- 

 perature, they positively refuse to feed, and in exactly the same stage as 

 they leave the &%%, pass through the winter, awaiting the first warm 

 day of spring before partaking of their first food." 



The second chapter is devoted to a discussion of the gregarious habit 

 in butterfl}' larvae, interesting series being traced from such caterpillars 

 as live solitary throughout their term — like Pieris napi and Pyrameis 

 cardui, though those that have an imperfectly developed social life like 

 Pieris rapce, and to the truly gregarious species like P. hrassicce and Aglais 

 urtica:. The web formed by the common labour of the larvae in the last- 

 named and in other species is an additional development of the social habit 

 Further in A. tirticce, as also in Vatiessa io, the larvae scatter to some extent 

 at least as they approach maturity, while in V. antiopa and Eugonia poly- 

 chloros they remain gregarious until pupation. 



After this valuable discussion, Mr. Tutt gives us nine short chapters 

 on " Family Habits in Butterfly Larvae," taking a family or section of 

 butterflies, and giving a general account of the larval habits to be noticed 

 in its species. The particular habit usual in a certain family or genus 

 are by no means universally followed by all its species; as might be 

 expected, the field is one in which adaptation is constantly modifying 

 instinct, and " the general impression bristles with exceptions." Among 

 the Satyridae, however, all the protectively-coloured, grass-feeding 

 larv£e live through the winter ; only occasionally does the caterpillar of 

 Pararge egeria pupate in autumn. 



The great part of the volume contains a continuation of Mr. Tutt's 

 survey of the family Ivycaenidae, or — as he prefers to call it — Ruralidae. 

 How full his descriptions are may be gathered from the fact that in 400 

 pages he deals with only seven species. The general plan is the same 

 as in previous volumes, and the long lists of British, Irish, and Conti- 

 nental localities are given in the confusing and unsystematic manner to 

 which we have before alluded. Thus of our familiar " Green Hairstreak " 

 — Callophrys rndi— it is stated "Very strangely localised in England, Ireland, 

 and Scotland, abundant in some counties, apparently quite absent in 

 others." But in order to make out how the distribution is localised, the 

 reader must wade through two pages of closely printed type, with the 

 counties arranged alphabetically, e.g., Carnarvon, Clackmannan, Cork, 



