28 SMITHSONIAN MISCELLANEOUS COLLECTIONS VOL. 63 



with hue hairs. He thinks that these structures perform a function 

 combining those of smell and touch. 



Bergmann and Leuckart (1852) say that when one brings a drop 

 of ether on the tip of a needle near the head of an insect it moves 

 and strokes its antennae. They speak of many pits on the antennae ; 

 from the base of these pits arise small papillae which they regard as 

 olfactory organs. 



Leydig (i860, 1886) made a thorough investigation of the pore 

 plates discovered by Erichson. He found these pore plates not only 

 in the antennas of most insects but also discovered that they are modi- 

 fied into peculiar, peglike organs in the remaining insects, and in the 

 crustaceans and myriapods. Leydig regarded these organs of ques- 

 tionable function as olfactory. In i860 he thought that the palpi 

 have a function similar to that of the antennae. 



Lespes (1858) compares the pore plates to the ears of higher ani- 

 mals and denies their olfactory office. 



Hicks (1859b and c) thinks that the pore plates are cavities filled 

 with fluid, closed in from the outer air by a delicate membrane to 

 which a nerve is attached. He regards the pore plates as auditory 

 organs and says : 



If we assign an olfactory function to these organs, one difficulty presents 

 itself, viz : that for the odorous particles to affect the nerve they must reach 

 it through a membrane and a stratum of fluid. 



Landois (1868) experimented with the stag beetle (Lucanus 

 cervus). He does not doubt that this beetle can smell, for if exposed 

 to the fumes of sulphuric acid, or ammonia or to tobacco smoke it 

 draws in its antennas quickly. If the ends of the antennae are removed 

 it still draws in the remainder of these appendages with the same 

 rapidity as when the antennae are intact. He found two kinds of 

 sense hairs on the antennae of this insect and pits filled with small 

 hairs. He thinks, however, that olfaction is performed by none of 

 these organs. 



Grimm (1869) describes three kinds of hairs and a pitlike organ 

 on the antennas of beetles but does not regard any of these as an 

 olfactory apparatus. He put a beetle with entire antennae into a box 

 which had a glass cover and an opening at the bottom covered with 

 thin cloth. After this beetle had become quiet he put a piece of dung 

 to the opening. The beetle at once came to the opening and tried to 

 tear the cloth. Later he cut oilf its antennae and repeated the experi- 

 ment, and the beetle came to the opening as before. By repeating 

 these experiments many times he concluded that the antennae of 



