August 5, iS8o] 



NATURE 



315 



quite different from those of the larva or the rudimentary 

 jaws of the perfect insect. These are to enable the pupa 

 to cut its way through the cocoon and outer case, when 

 it is ready to assume the perfect state. It then becomes 

 active, swimming by means of its two middle legs, the 

 tarsi of which are densely fringed with long cili?e, forming 

 admirable oars. By means of these the pupa reaches the 

 stem of some aquatic plant, up which it creeps out of the 

 water, and then sheds its pupa-skin, and lives a short 

 aerial life which seems wholly devoted to the duty of 

 continuing the species. 



From the foregoing brief sketch of the main features of 

 this order of insects, it will be seen that they form what 

 is probably a very ancient group, which has preserved 

 some of the characteristics of several distinct orders- 

 Though, owing to the structure of the rudimentary mouth, 

 the Trichopterahave to be classed among the mandibulate 

 or gnawing insects, and are supposed to be allied to both 

 the Neuroptera and the lower Hymenoptera, yet in the 

 neuration of the wings, their hairy clothing, the silk- 

 spinning and case-bearing larva?, and the form and habits 

 of the perfect insect, they more nearly resemble some of 

 the smaller moths, with which Mr. McLachlan believes 

 they have a real affinity. So, in the curious activity of an 

 otherwise quiescent pupa, which possesses special organs 

 for gnawing and for swimming, these insects seem inter- 

 mediate between the groups with an imperfect and those 

 with a perfect metamorphosis, though far more closely 

 allied to the latter ; and owing to these various peculiari- 

 ties the Trichoptera may be said to constitute a "critical" 

 group, whose study cannot fail to throw light on the 

 affinities and genealogy of insects generally. Owing 

 however to their obscure colours and slightly varied 

 forms they have attracted comparatively little attention, 

 though a few ardent workers have for many years devoted 

 themselves to this branch of entomology ; but the appear- 

 ance of the present elaborate work, which is a model of 

 conscientious labour and research, will form an important 

 era in the study of the group. 



This large and handsome octavo volume is devoted to 

 a complete description of all the species of Trichoptera 

 which have been discovered in Europe and Northern 

 Asia, or in what is now termed the Patearctic Region. 

 These descriptions have all been drawn up from speci- 

 mens of the insects themselves— often of the greatest 

 rarity— and the fact that the _chief museums and private 

 cabinets of Europe and America have placed their 

 collections in Mr. McLachlan's hands for the pur- 

 poses of this work, is the best proof of the high repu- 

 tation he has attained as a master in this branch of 

 entomology. The book is illustrated by fifty-nine plates 

 containing about 2,000 distinct figures (all drawn by the 

 author himself), illustrating generic and specific characters 

 mostly derived from the neuration of the wings and the 

 structure of the anal appendages. These latter organs 

 are wonderfully varied from species to species while 

 constant in each ; and by carefully delineating them by 

 means of the camera litcida, species have been shown to 

 be distinct which appear in all other respects to be iden- 

 tical ; and the fact of such distinctness in a considerable 

 number of cases is one of the most curious and interesting 

 results of Mr. iMcLachlan's researches. 



The work has occupied nearly six years in its publica- 



tion, and it has had the effect of stimulating inquiry to 

 such an extent that a large number of new species have 

 been discovered during its progress,>endering the book 

 half as large again as was anticipated; yet the author 

 believes that a comparatively small portion only of the 

 European species are yet known, while in less familiar 

 regions there is a wide field for the discovery of new and 

 remarkable forms. There remain also a number of larvre 

 which have not been identified with the perfect insect, 

 and an interesting and useful line of observation is thus 

 open to entomologists both at home and abroad. Under 

 these circumstances every naturalist will appreciate the 

 value of a work which has collected together and 

 thoroughly worked up all the material available to the 

 latest date. Such a book cannot,' from its nature, be a 

 popular one. Its production has been a labour of love, 

 and is to that extent its own reward ; but the expense of 

 producing such a volume is very great, and in order to 

 encourage and even to render possible the production 

 of such works it becomes the duty of all who wish to 

 advance the study of nature to do what in them lies to 

 relieve such enthusiastic workers from the pecuniary 

 burthen which their self-denying labour brings upon 

 them. If evei-y scientific institution and every Natu- 

 ralist's Field Club in the kingdom were to purchase a 

 copy of this admirable volume for the use and instruction 

 of their members, they would do much to render the pro- 

 duction of such works more common, besides really 

 furthering the progress of research, perhaps even more 

 than by the publication in full of their own Proceedings. 



This is undoubtedly the most important British work 

 on Entomology since the completion of Mr. Stainton's 

 "Natural History of the Tineina" thirteen years ago, and 

 it is well worthy of the high reputation of its author ; 

 while the clearness of the type, the excellent systematic 

 arrangement, the full indices, and the beautifully engraved 

 figures, are equally commendable. Any detailed criticism 

 on such a book could only be given by a worker in the 

 same group ; but as one who has often to refer to natural 

 history volumes for information, the present writer would 

 suggest that the absence of a.nyfaiinfy names as headings 

 to the pages is a great inconvenience, as there is no 

 means of ascertaining what group a genus belongs to or 

 of finding the commencement or end of a family without 

 constantly turning to the index. So far as the typography 

 and general arrangement of the volume are concerned 

 this is the only defect that has been noticed, and that it 

 is so small a one may be taken as an indication of the 

 care and attention which has been bestowed upon the 

 publication, no less than on the composition of this 

 notable volume. A. R. \V. 



OUR BOOK SHELF 



Ormthological Journal of the Winter of 1878-79; with 

 Collected Notes regarding its Effects upon Animal Life, 

 including Remarks on the Migration of Birds in the 

 Autumn of 1878 and the Spring of 1879. By John A. 

 Harvie-Brown, F.Z.S., M.B.O.U. {Proc. Nat. Hist. 

 Soc, Glasgow, 1879.) 



Mr. Harvie-Brown, well known as one of the most 

 active and practical of our home-ornithologists, has 

 endeavoured to chronicle the abnormal effects of an 



