NA TURE 



THURSDAY, Al'GL'ST 8, 1895. 



THE STUDY OF INSECTS. 

 A Manual for the Study of Insects. B\- Prof. John Hcnrj- 

 Comstock and Anna Botsford Comstock. I'p. 701. 

 (Ithaca, X.Y. : Comstock, 1895.) 



THE present work is very much on the same lines 

 as Dr. Packard's well-known ''(luide to the -Study 

 of Insects," though somewhat more popular, and dealing 

 still more exclusively with North American entomology, 

 of which, on the whole, it furnishes an admirable com- 

 pendium. It is got up in a verj- attractive form, and is 

 crowded with illustrations, the woodcuts being chiefly 

 from engravings from nature by Mrs. Comstock. 



The first chapter is devoted to a brief e.xplanation of 

 the principles of zoological classification and nomen- 

 clature, in the course of which we meet with a system 

 of trinomial nomenclature for sub-species, or constant 

 varieties, which has not hitherto been much patronised 

 by entomologists. Thus, with reference to a common 

 American swallow-tail. Prof Comstock writes : 



" This name, Jasoniades glaucus, is used when re- 

 ference is made to the species as a whole. But if one 

 wishes to refer to the black form alone, it is distinguished 

 as Jasoniades glaucus };laucus ; while the yellow form 

 is distinguished i\s Jasoniades i^laucus turnus." 



Surely this is too complicated and clumsy a system 

 for ordinary use ! 



The second chapter deals w ith " Insects and their near 

 relatives," and includes a brief definition of the branch 

 (or, as it is more commonly called in England, sub- 

 kingdom) .Xrthropoda, and a table of the four classes 

 Crustacea, Arachnida, Myriapoda, and Hexapoda, or 

 insects. The Crustacea and Myriapoda arc very briefly 

 noticed, though a few typical forms of each are figured ; 

 but the Arachnida recei\e more attention, the orders 

 and principal families, especially of the Arancida, being 

 briefly discussed, with notices of their chief peculiarities 

 and habits. .\s an illustration of the author's style in 

 the more popular parts of his book, as well as embody- 

 ing a curious phase of cannibalism, we may c|uote the 

 following passage from p. 24 : — 



" Fig. 23 represents the large egg-sac of one of the 

 cobweavers. This is made in the autumn, and contains 

 at that season a large number of eggs — five hundred or 

 more. These eggs hatch early in the winter ; but no 

 spiders emerge from the egg-sac until the following 

 spring. If egg-sacs of this kind be opened at different 

 times during the winter, as was done by Dr. Wilder, 

 1 the spiders will be found to increase in size, but diminish 

 in number as the season advances. In fact, a strange 

 tragedy goes on within these egg-sacs ; the stronger 

 spiders calmly devour their weaker brethren, and in the 

 spring, those which survive emerge sufficiently nourished 

 to fight their battles in the outside world." 



The remaining chapters are taken up with a sketch 

 of the seventeen orders of insects admitted by Prof 

 Comstock, with special, and indeed almost exclusive, 

 reference to the North .•\merican species. These chapters 

 diflbr very much in length and importance, the space 

 allotted to some of the smaller orders being barely a 

 couple of pages, while the chapter on I.epidoptera alone 

 01 (uincs nearly a third of the volume. 

 NO. 1345. VOL. 52] 



The interest of the book is much enhanced by the 

 illustrations ; and in speaking of the Mendiracidie, one 

 of the families of Hontoptera, Dr. Comstock observes : 

 " .Nature must have been in a joking mood when tree- 

 hoppers were developed " ; and the row of " odd fellows " 

 at the foot of p. 154, where this observation occurs, fully 

 bears out the remark. 



But it must not be supposed that this book is too 

 popular to appeal to serious students ; far from it. Some 

 of the smaller orders of insects are, indeed, passed over 

 with but slight notice ; but in the larger ones, we meet 

 with elaborate descriptions of structure, and dichotomous 

 tables of the principal families, which are afterwards 

 discussed in greater detail, and in most cases one or 

 more of the representative .American species are figured, 

 frequently with transformations. 



.Vlthough, as a rule, .\merica suffers more from insect 

 pests than Europe, yet there seem to be exceptions which 

 we should hardly anticipate. Thus Prof Comstock in 

 forms us (p. 103; that " The earwigs are rare in the .Nortli- 

 Eastern United States, but are more often found in the 

 South and on the Pacific coast," and the native .American 

 cockroaches also are regarded by him (p. 106) as harm- 

 less, the destructive species, as in England, being all 

 imported insects. Among these, he mentions the " Croton 

 Bug," as he calls Phyllodromia germanica, as infesting 

 "the vicinity of the pipes of the water-systems of many 

 of our cities." In England, this species is particularly 

 numerous m bakeries. 



Under the Ftdgoridce (Lantern-flies), Prof Comstock 

 refers to "the fact that they are phosphorescent," ap- 

 parently being unaware that the statement is very greatly 

 doubted, though it is perhaps premature to say that it 

 has been actually disproved. 



-A great many figures of neuration of Lepidoptera and 

 other insects are given, all numbered according to a 

 uniform system which Prof Comstock has adopted 

 from Redtenbacher, with modifications of his own, but 

 which is unfortunately not fully explained in the work 

 before us. 



English names are given to most of the insects noticed, 

 some of them being rather grotesque. Thus, at p. 274, 

 we find a figure of ''The Firstborn (leometer" {Hrephos 

 in/ans), with the explanation on the following page : 

 " .\s this is probably the most primitive geometer occur- 

 ring in our fauna, we suggest the popular name Firstborn 

 for it." This is not the first occasion on which we have 

 had occasion to animadvert on the introduction of crude 

 speculations on the course of evolution, as if they were 

 established or probable facts. 



It is perhaps worth noticing that Prof Comstock 

 places the Lepidoptera between the Mynneleonidce and 

 the Diptera. He has a peculiar classification of his own, 

 which we have not space to indicate in detail ; but he 

 makes the Ilepialidic and Micropterygidu- a separate 

 sub-order under the name of Jugatcc, and after it he 

 places the Frenatcc, in which he includes all the re- 

 maining families, commencing with the Megalopygidie, 

 l'.tychid(r, Cossidce, &c., and ending with the "super- 

 family " Satur/tiina, the " families " Lacosomidie and 

 LasiocampidiT (apparenth- not referred to any "super- 

 family"), and the butterflies, including the "super-families" 

 Hesperiimx and I'apilionina, in a reversed order, terminal- 



