232 THE entomologist's eecord. 



ance of Vol. II will be a matter of general congratulation amongst 

 naturalists. 



Mr. Tutt's work aims at being in the first place a complete collec- 

 tion of all that is as yet known of the natural history of the species dealt 

 with. These books are no mere compilation, but in the fullest sense 

 original treatises. No pains have been spared to get together every- 

 thing that relates to the structure, distribution, variation, life-history 

 and habits of each form in its several stages. Many of the facts thus 

 given are new, a large part being the results of the author's own 

 direct observation. Moreover, much of the information here published 

 has been communicated privately to Mr. Tutt by his numerous 

 correspondents, and the mass of facts given at first hand is thus 

 greatly increased. This is especially the case in regard to the life- 

 histories, which in very many instances have been worked through in 

 minute detail by Mr. Tutt and his coadjutors expressly for this book. 

 Owing to the wide appeal which the author has made to living 

 entomologists for such personal records, and to his laborious researches 

 into the literature already printed, the books probably represent the 

 sum of existing knowledge on the subjects contained. 



It is a special charm of Mr. Tutt's treatise that the reader has a 

 comfortable sense that his author is giving him no scamped work. 

 Everything capable of verification has been verified, and nothing is 

 repeated in slovenly fashion unchecked. For such a work not only 

 professed entomologists, but all naturalists who from time to time 

 require precise information as to lepidoptera, will be grateful to Mr. 

 Tutt, and his books will be required in every working library of 

 natural history. Nothing of the kind has hitherto been attempted, 

 and by reference to them much searching and weary correspondence 

 will be avoided. 



The present volume deals with the Psychides and part of the 

 Lachneides. Whether the views adopted by Mr. Tutt on questions 

 of classification and the like are sound or not can, of course, only be 

 judged by specialists, but it will be evident to any student of zoology 

 that he has attacked these problems in a most fruitful way, and that 

 in each of the numerous discussions of special questions he has pro- 

 vided a marshalling of the facts which Avill help succeeding students. 

 Several sections of this kind are introduced relating to general 

 questions of the morphology of lepidoptera, especially the nature of 

 metamorphosis and the structure of pupae. In addition to these there 

 is an important chapter written by Dr. T. A. Chapman on the 

 phylogeny of the lepidopterous pupa, a subject on which he is the 

 recognised authority. 



In connection with the significance of larval moults, reference is 

 made to the interesting observations of Chapman on variation in 

 number of moults in Arctia caia, but there appears to be no account 

 of Dyar's remarkable evidence relating to similar variations. Accord- 

 ing to Dyar's observations on several species, the larva — as measured 

 by the width of the head — increases in size at each moult in a definite 

 geometrical ratio, and when stages are added or omitted the ratio is 

 halved or doubled accordingly. It is most desirable that further 

 investigation of this curious phenomenon should be made, and it 

 would have been well to direct the attention of students to the subject. 

 It is noticeable that while morphologists, in reasoning based an 



