54 N. E. McINDOO 



SUMMARY 



The disposition of the olfactory pores of Lepidoptera is similar 

 to that of Hymenoptera and Coleoptera, but resembles the former 

 more closely. The structure of these pores is also similar to that 

 of those found in other insects, but differs slightly in three fol- 

 lowing respects: The external ends of those in Lepidoptera are 

 dome-shaped and the only other dome-shaped ones found by the 

 writer are in the lady-beetle, Epilachna borealis. The external 

 .boundary of the cones may be convex, almost flat, and concave, 

 but hitherto it has always been convex. The sense cells are 

 more spherical than usual. 



Compared with the antennal organs, the olfactory pores are 

 better adapted anatomically to receive olfactory stimuli, be- 

 cause the peripheral ends of their sense fibers come in direct 

 contact with the external air, while those in the antennal organs 

 are covered with hard chitin. 



LITERATURE CITED 



Freiling, Hans H. 1909 Duftorgane der weiblichen Schmetterlinge nebst 

 Beitragen zur Kenntnis der Sinnesorgane auf dem Schmetterlings- 

 flijgel und der Duftpinsel der Miinnchen von Danais und Euploea. 

 Zeitsch. f. wiss. ZooL, Bd. 92. 



GuENTHER, KoNRAD 1901 tjber Nervenendigungen auf dem Schmetterlings- 

 fliigel. Zool. Jahrb., Anat., vol. 14. 



Hauser, Gustav 1880 Physiologische und histologische Untersuchungen liber 

 das Geruchsorgan der Insekten. Zeitsch. f. wiss. ZooL, Bd. 34. 



Hicks, J. B. 1857 On a new organ in insects. Jour. Linn. Soc, London, 

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1859 On a new structure in the antennae of insects. Trans. Linn. 

 Soc, London, vol. 22. 



1860 On certain sensory organs in insects, hitherto undescribed. 

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McIndoo, N. E. 1914 a The olfactory sense of the honey bee. Jour. Exp. 

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1914 b The olfactory sense of Hymenoptera. Proc. PhiUi. Acad. Nat. 

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1914 c The olfactory sense of insects. Smithsonian Misc. Collec, 

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1915 The olfactory sense of Coleoptera. Biol. BuL. vol. 28. 



1916 The sense organs on the mouth-parts of the honey bee. Smith- 

 sonian Misc. Collec, vol. 65, no. 14. 



ScHENK, Otto 1902 Die antennalen Hautsinnesorgane einiger Lepidopteren 

 und Hymenopteren, mit besonderer Beriicksichtigung der sexuellen 

 Unterscheide. Zool. Jahrb., Bd. 17. 



