54 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 68 



Miiller (i878a-b) ascertained that the strong musky odor of a 

 certain Brazilian sphinx moth comes from the organ described above. 



Arnhart (1879) found a similar organ in Acheronfia atropos. 



Fiigner (1880) saw the same organ in Sphinx ligustri. The odor 

 emitted is musklike. 



Von Reichenau (i88oa-b) first described this organ in Sphinx 

 ligustri. He says that a muscle is attached to the base of the hairs 

 so that they may be expanded. Each hair is hollow and is filled with 

 a secretion emitting a musky odor. 



Hall (1883) noticed that Acherontia atropos emits a musky odor 

 when the thorax is compressed. 



Bertkau (1884. 1887) describes this type of organ as a shallow 

 pocket, lined with hairs, in the pleura of the first and second abdominal 

 segments. The slit-shaped opening of this longitudinal pocket is 

 securely closed by hairs and it lies near the posterior edge of the 

 pleuron of the second segment. Muscle fibers are present at the 

 bases of the hairs and at the bottom of the pocket. The chitin is 

 perforated by many fine pores, and from each pore runs a secreting 

 tubule to a unicellular gland which is a modified hypodermal cell. 



Haase (1884, 1886a) calls this type of organ in Acherontia a 

 secondary sexual character because it is found only in the males. The 

 hairs serve chiefly to spread the volatile oil which issues from the 

 pores at the bottom of the pocket. During a forced expiration the 

 hairs spread out raylike and thus greatly increase the available sur- 

 face to assure a quicker evaporation of the oil. 



Pollack (1887) observed similar scent-producing organs in Hadena 

 atriplicis and H. litargyria. 



Illig (1902) considers this organ in Acherontia atropos and Sphinx 

 ligustri as a bunch of hair lying in a longitudinal groove, located as 

 already stated. A large unicellular gland is connected with the base 

 of each hair. Since the surface of the hair has longitudinal ridges 

 and because the chitin between these ridges at times appears porous, 

 it may be assumed that the secretion infiltrates through the apparent 

 pores, 



9. VARIOUS STRUCTURES AT VENTRO-POSTERIOR END OF ABDOMEN OF 

 CERTAIN LEPIDOPTERA AS SCENT-PRODUCING ORGANS 



(a) INVAGINATZD SACS, TUFTS OF HAIR AND SCENT GROOVE OF CERTAIN MOTHS 



^Morrison (1874) saw two long, pale-yellow and hairy appendages 

 projecting from under the extreme end of the abdomen of a male 

 Leucarctia acrccc. 



