OLFACTORY ORGANS OF LEPIDOPTERA 



49 



lie in each vein, and that one of the sections passed through an 

 isolated pore in the costa of the hind wing (fig. 6 B, P). 



To understand the anatomy of the legs at the position where 

 the olfactory pores lie, the reader is referred to figure 7, which is 

 a semidiagrammatic drawing taken from one section cut obliquely 

 across the femur, trochanter and coxa. In dead insects the femur 



Fig. 8 Cross sections, showing internal anatomy of olfactory pores of other 

 moths, X 506. A to G, from wings; H, from trochanter; and I, from femur. 

 A, B and H, from catalpa sphinx, Ceratomia catalpse. B is cut obliquely; C, 

 D and I, from lesser wax moth, Achroia grisella; E, from Prodenia ornithogalli; 

 F, from Atteva aurea; and G, from front wing of tussock moth. HypS, hypo- 

 dermal secretion forming cone; A"^, nerve; NB, nerve branch; PorAp, pore aper- 

 ture; Tr, trachea. 



and trochanter form a right angle with the coxa, and this fact 

 explains how an oblique section may be cut passing through all 

 three segments. This section passed through groups nos. 8, 

 10 and 11, no. 10 being shown partially in cross section and 

 partially from a superficial view. Most of the muscles (Me) 

 are cut longitudinally, but those near the sense cells (SC) run 

 transversely, leaving a space, the blood sinus (BlSin), in which 

 the sense cells lie. The nerve branch (NB) leaves the nerve 



JOURNAL OF MORPHOLOGY, VOL. 



