146 Mr. W. S. MacLcay on the Anatomy of the 



counteracted in time, and as you ask me for such a paper, I hope what 

 I now send will answer your purposes. 



Yours ever most truly, 



W. S. MacLeay. 

 Havana, 2nd October, 1829. 



I find it impossible to give, according to the present state of the science 

 in England, any satisfactory description of insects, without making some 

 previous observations on their anatomical nomenclature. My object now 

 therefore is to explain to entomologists a few of the principles by which 

 I shall be guided in my future descriptions. 



Eight years have elapsed since the second part of the " HorcB Entomo- 

 logiccB'^ was published. In this work I gave incidentally an outhne of the 

 theory of comparative anatomy so far as it related to the subkingdom of 

 Annulosa, and as it was known at the time. Since then indeed three 

 works have appeared, all treating of this most difficult subject with more 

 or less philosophical rigour and critical acumen, but all three apparently 

 having very different objects in view. 



The first of these in point of patient labour are the very ingenious and 

 detailed memoirs of M. Chabrier on the Anatomy of the Organs of Flight 

 in various Insects, which were published in the " Memoires du Museum 

 " d'Histoire JVaturelle.''^ The object of these memoirs is not to give a 

 strictly comparative view of the anatomy, so much as to shew the internal 

 and external structure of the various organs that have an influence on the 

 flight of insects. This is a work therefore rather .important for the infor- 

 mation it affords as to facts, than for the generalization of them. 



Immediately afterwards M. Audouin published in the first volume of 

 the "Annates des Sciences Matur elks' ''^ the first part of his " Recherches 

 " Anatomiques'suT le Thorax des Animaux Ariicules, et celui des Insectes 

 " Hexapodes en particulier," which researches he announced it to be his 

 intention to continue in the same Journal. They had long before been 

 laid on the table of the Institute, indeed previously to the appearance of 

 M. Chabrier's Memoires, and had been most favorably reported on by 

 M. Cuvier as the president of a commission appointed to examine them.f 



* Published in 1824. 



^ See " Rapport fait a I'Acadeniie des Sciences de Paris dans la Seance du 



