OF THE SKELETON. 135 



and retention is the power of preserving an image left on the 

 mind by an event that has occurred. Of the connexion of 

 mind with the organs which it commands we know nothing ; 

 mind itself is only known by its effects : its commands 

 are carried by the nerves ; a fact ascertained by separating 

 a nerve ; after which separation, the mind no longer con- 

 trols the parts to which that nerve extended its branches. 



The physiology of insects is, however, properly confined 

 to the description of their systems of organs, and to the 

 functions which these organs perform : therefore, excepting 

 as connected with the organs, no further notice will be taken 

 of any other element than matter. 



With regard to the anatomical nomenclature employed 

 in the following pages, it will be, perhaps, advisable to 

 make one or two observations. The author has studiously 

 guarded against the admission of those terms which are of 

 recent date, and seem invented without any other object 

 than that of caprice : in every instance he goes back to the 

 earliest name of which the meaning is clearly defined : he 

 has invented no name except for parts which he found 

 totally nameless. The authorities for the nomenclature of 

 the external or osseous parts of insects, are Fabricius, Sa- 

 vigny, Audouin, and Straus-Durckheim. The labours of 

 Fabricius and Savigny have been noticed with tolerable 

 accuracy in Kirby and Spence's * Introduction to Ento- 

 mology'; those of Audouin with more skill by Mr. Mac- 

 Leay, in the ' Zoological Journal' ; and those of Straus 

 by Mr. Doubleday, in the ' Entomological Magazine.' 

 The author of this work has attempted to build a uniform 

 anatomical nomenclature on his own observations, seeking 

 amid these learned authors for the prior name given to 

 each part : a portion of the result was published in the 

 ' Entomological Magazine' under the title of Osteology of 

 Insects, but the subject not being adapted to the taste of 



