38 



N. E. McINDOO 



The number of pores in each group on the right leg is as follows : 

 Front leg, no. 8—10, no. 9—8, no. 10—9, no. 11—9; middle leg, 

 no. 8—11, no. 9—6, no. 10—6, no. 11—8, hind leg, no. 8—11, 

 no. 9 — 6, no. 10 — 8, and no. 11 — 8. The variation in the num- 

 ber of pores on the left legs is very similar to that just given. 



Fig. 2 Portions of legs of Bombyx mori 9 , showing location of groups nos. 

 8 to 10 of olfactory pores on the trochanters, no. 11 and a on the femurs, X 192. 

 A and B, outer and inner surfaces of right front leg respectively; C and D, same 

 of right middle leg; and E and F, same of right hind leg. 



All six legs of the specimen of Bombyx mori 9 examined bear 

 218 olfactory pores; the front wings carry 423 pores, and the 

 hind wings carry 420 pores; no pores were observed on the 

 mouth parts; all of these combined make 1061 olfactory pores. 



h. Other species. The greatest variation found in the olfactory 

 pores of the other species examined is in regard to the total num- 

 bers of the pores. On the average, butterflies have only two- 

 thirds as many pores as have moths ; this difference is due solely 



