EXTERNAL ANATOMY OF INSECTS. 459 



Before I call your attention to what I would' denomi- 

 nate an imperfect month, in which some one or more of 

 the seven organs above enumerated exist under another 

 form, or only as rudiments, — I must say something upon 

 the mouth of the Myriapods and Arachnida, in which 

 there seem to be redundant organs of manducation. — 

 M. Latreille, in the Essay lately quoted, in which, 

 though some of his notions seem fanciful, he has shown 

 a vast depth and range of thought and research, has as- 

 serted, — from the admirable and curious observations of 

 M. Savigny, and those which since their publication he 

 has made himself, — that the masticating organs of an- 

 nulose animals (called by him condylopes) are a kind of 

 legs a . And M. Savigny, whose indefatigable labours 

 and unparalleled acuteness have opened the door to a 

 new and vast field in what may be denominated analo- 

 gical anatomy, — has observed, that with certain Apiro- 

 pods b the organs that serve for manducation do not dif- 

 fer essentially from those which, with the other Apiro- 

 pods and the Hexapods, serve for locomotion c : and the 

 unguiform mandibles of the larvae of certain Diptera, 

 you have before been told, are used not only in mandu- 

 cation, but also as legs d . These remarks will satisfac- 

 torily prove to you, that organs which at first sight pos- 

 sess no visible affinity or analogy — as for instance, jaws 

 and legs — may, if traced through a long series of beings, 

 exhibit a very great one ; — and will lessen your surprise 



a Organisation &c. 182. 



b Under this name M. Savigny includes the Myriapoda, Arach- 

 nida, and Crustacea. Anim. sans Vertebr. I. i. 40. 

 c Ibid. 43. 

 d Vol. II. p. 275 — . Also see abovc^ p. 121 — . 



