1G2 [July, 



it, compiled on the same lines and with equal elaboration and attention to details 

 we may expect a fund of information, for collectors as well as students, such as has 

 never before been brought together in so accessible and convenient a form. The 

 work is prefaced by nine chapters devoted to a summary of the researches of other 

 authors on the origin, embryology, larval structure, protective or other variation and 

 classification of tliis order of insects. After numerous quotations, and more or less 

 comparison of the conclusions arrived at by others, Mr. Tutt appears to accept the 

 " pretty generally " received opinion " that the Lepidoptera and Trichoptera 

 originated from a common Neuropterous stock " from which same source he thinks 

 the Diptera also probably arose, originating quite independently " from a common 

 ancestral base." His second chapter, dealing with the ovum, is a very careful study 

 of the form, pattern and position of the eggs of Lepidoptera undertaken with a view 

 to assist the author in his efforts to arrive at some reliable conclusion as to the 

 origin and relationship of the various groups and families, so far as such evidence 

 can enable him to do so. It would seem that he is rather inclined to overrate the 

 importance of this branch of his subject for purposes of classification. There is 

 undoubtedly a resemblance, or uniformity of shape and colour, in the eggs of birds by 

 which on ornithologist might be enabled to guess at certain families, the ducks, the 

 owls, the hawks, or the divers, for instance ; in Entomology however we cannot look 

 upon this as a real aid to classification, but rather as mere collateral evidence. The 

 question of the internal or external position of the egg and its consequent passage 

 through an extended and sharply pointed, or an obtuse and less chitinous ovipositor, 

 may surely be taken to account for many variations in the eggs of Lepidoptera 

 belonging to the same family or even to the same genus. The author would 

 probably be the first to admit that classification founded simply upon oval characters 

 must necessarily fail to be of taxonomic value. After two chapters on embryology, 

 and parthenogenesis respectively, in which he admits that the modus operandi of 

 parthenogenesis in Lepidoptera is still as obscure as ever, although he offers the 

 suggestion that the potency of the male element is handed down through many 

 generations, he proceeds to consider, in chapter 5, the external structure of the 

 Lepidopterous larva. This chapter contains an excellent description of the anatomy 

 of larvK of different types, with copious quotations from the writings of Dyar, 

 Chapman, Scudder, and Packai-d, and allusions to the views of Fritz Miiller, 

 Meldola, Poulton and others. Another chapter is devoted to the internal structui'e 

 in which the muscular, ganglionic and respiratory systems as well as the nature and 

 functions of the blood are discussed, but he omits in this chapter any reference to 

 the curious chin glands (subsequently referred to under protective and defensive 

 structures on p. 94) which are so noticeable in MelitcBa and other larvaa of butter- 

 flies, as well as in certain groups of the Noctuida, and which have sometimes been 

 regarded as designed for the lubrication of food rather than for any defensive 

 purpose. 



The defensive and protective effect of colour- variation, the prevalence of 

 seasonal dimorphism, and the potential operation of natural selection are elaborately 

 referred to ; the views of Wallace, Weismann, Standfuss and others being brought 

 into contribution, with the general result that although the author appears to regard 

 temperature as the external stimulus mainly regulating the range of variation in the 

 determinants of the scales, which enables the insect to assume different shades of 



