524 HENRY M. BERNARD, Origin of the tracheae. 



origin of the coxal glauds of the Arachnids. It is obvious, however, 

 that our derivation of trachea3 from setiparous glands is not seriously 

 aliected, if we leave these glands entirely out of consideration. On 

 the other hand, if it can be shown that the coxal glands of the Arach- 

 nida are developments of Annelidan acicular or setiparous glands, the 

 argument brought forward in this paper would be considerably 

 strengthened. 



