139 



of our science during the past year; in doing which, it will be neces- 

 sary, in some instances, to refer to books or memoirs published pre- 

 viously to 1851, but of which we have only obtained a knowledge 

 during the past year. The necessity of these annual summaries of 

 publications connected with Entomology is every day becoming more 

 evident, from the multiplicity of channels in which new facts are re- 

 corded, and new species described or old ones illustrated. I am aware 

 how difficult is the task which I have undertaken ; but I trust few 

 material omissions will be found in my summary, by which, with the 

 assistance of those published by Burmeister and Erichson, and, since 

 the decease of the latter, continued by Schaum in Germany, and by 

 Bohemann in Sweden, the future entomological bibliographer will 

 find his labours greatly relieved, and the means afforded of obtaining 

 a knowledge of the majority of the publications, and consequently an 

 idea of the state of the science at any particular period. 



The plan which I propose to adopt in the following pages, is to 

 classify these publications according to the orders and families upon 

 which they treat, — a more useful, but, at the same time, a far more la- 

 borious plan than has been generally adopted by my predecessors, in 

 their annual addresses from this chair. 



I must, however, in the first place, direct your attention to the pub- 

 lication of the first volume of the ' Insecta Britannica,' published 

 under the superintendence of the Officers of this Society, destined to 

 supply the want, which has been so long felt, of a descriptive work 

 upon those orders of insects which have not hitherto been described 

 in detail in this country, or which have been found to require revision. 

 The orders intended to be treated upon in the present series, are the 

 Diptera, Hemiptera, Homoptera, and Micro-Lepidoptera ; and it is 

 confidently hoped that the support of the public will warrant a future 

 series. 



Entomology and Insects in general. 



A remarkable memoir by Professor Louis Agassiz, on ' tbe Classification of Insects 

 from Embryological Data,' bas appeared in the 2nd vol. of tbe ' Smithsonian Contribu- 

 tions to Knowledge,' 4to., Washington, 1851. Taking up the idea (first propounded, 

 I believe, by MacLeay) that the perfect state of one animal is represented by one or 

 other of the preparatory states of another animal higher in organization than itself, and 

 working out the assertion of Oken, that Lepidoptera are born as worms, then pass into the 

 the condition of Crustacea, and are finally developed into true insects, thus exemplifying 

 the natural order of "radation of the three classes of Articulata, the author reviews the 



