50 



SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 8l 



scent hairs are attached to the anterior portion of the sac. When the 

 sac is evag'inated and the tuft of hair is expanded, this organ resembles 

 a cyHndrical fan whose contents are turned inside out to form the 

 circular part of the fan. The scent hairs are filled with a matrix 

 substance and the secretion passes through tiny pores in the walls of 

 the hairs to the exterior. 



Jordan (36) discovered in a number of Notodontidae a flap, which 

 he called a cteniophore. It is movable and partlv covers a cavity in 



Fk;. 16. — Scent-producing organ of a male codling moth. A, Cross section 

 through tip end of abdomen, showing location of a pair of invaginated sacs, which 

 are evaginated by muscles (Mti) thereby exposing the hairs (H) to the ex- 

 terior, X 53 ; B, longitudinal section through tip end of abdomen, showing 

 muscles (Mu) attached to invaginated sac filled with scent hairs (H) to which 

 are attached unicellular scent glands (Gc), X 53 ; C, cross section of scent hairs, 

 showing their spongy texture and pores (p) in outer wall, X 500; D, longitudinal 

 section through bases of two scent hairs (H) and their gland cells (Gc), X 500. 



the pleurum of the fourth abdominal segment. It is a special male 

 apparatus developed in connection with scent organs. He believed 

 that the hind tibia and hind wing were rubbed across the cteniophore 

 to receive an odorous substance, probably from glands in the cavity. 

 A remarkable combination of tympanic organ and cteniophore was 

 earlier discovered by Jordan and more recently pictured by Hering 

 (32, p. 195). In codling moths, a projection, probably a cteniophore, 

 lies on either side of the abdomen of the males, but no cavity is present. 



