124 Development zvithiu the Larva 



narrowing of tlieir bases seems to show that even the 

 prothoracic pair were articulated like wings \ though 

 their forward position seems hardly compatible with the 

 notion that they were serviceable in raising the body 

 from the ground. 



The patagia of Lepidoptera and Caddis-flies have been 

 identified with prothoracic wings by Cholodkowsky, but 

 Haase points out that they agree better with the tegulae 

 found on the mesothorax of certain insects. 



Fig. 9^. — Transverse section of late larva, showing : J\ fiitty 

 cells. <, tracheal gill of pupa. I, Ibre-leg. oe, oesophagus. 

 n, nerve-cord. 



It is to be observed, however, that the doreal protho- 

 racic rudiments, from which the pupal tracheal gills of 

 Chironomus j^roceed, are the last to be developed. It is 

 not till the larva is almost full-grown, and long after the 

 other thoracic appendages are visible, that they appear. 

 In the same way the corresponding organs of the blow- 

 fly, the prothoracic appendages of the pupa, are the only 

 imaginal rudiments which cannot be traced back to the 



' BroDgniart, Reck, pour servir a Vhistoire des Inscctes fussiles des ktnps 

 piiiiiaircs. 2 vols. 4to. St. Etienne, 1893. 



