/ ■/ 



/■ 



* 



Plate II. Pit sensilla on the antennae of the blowfly. 

 Fig. 1. Longitudinal section through a thin-walled sensillum. Note pits in 



cuticle (X 16,000). 

 Fig. 2. Longitudinal section through the tip of a thick-walled sensillum. Note 

 even reticular appearance of material within pits which are seen in transverse 



section (x 16,000). 

 Fig. 3. Longitudinal section through a thin-walled sensillum (x 56,000). 

 Fig. 4. Transverse section through a thin-walled sensillum. Note pits on left 

 where material within is seen in longitudinal section as parallel fibers or tubules 

 and pits at top where the same material is seen in transverse section ( ;< 28,000). 

 Fig. 5. Transverse section through the apical region of a thick-walled sensillum 



(X 14,000). 

 Fig. 6. Transverse section through a thin-walled sensillum (x 56,000). 



