SMELL. 413 



such as that of oil of turpentine, which is ex- 

 ceedingly offensive to all insects. It was only 

 when a fine camel-hair pencil containing this 

 pungent fluid was presented near the cavity of 

 the mouth, above the insection of the proboscis, 

 that any visible effect was produced upon the 

 insect, which then gave decisive indications of 

 strong aversion. Mr. Kirby has discovered in 

 the anterior part of the nose of the Necrophorus 

 vespillo, or burying-beetle, which is an insect 

 remarkable for the acuteness of its smell, a pair 

 of circular pulpy cushions, covered with a mem- 

 brane, beautifully marked with fine transverse 

 furrows. These he considers as the organs of 

 smell ; and he has found similar structures in 

 several other insects.* 



No distinct organs of smell have been disco- 

 vered in any of the Mollusca ;t but as there is 

 evidence that some of the animals belonging to 

 that class possess this sense, it has been con- 

 jectured that it resides either in the whole 

 mucous surface of the mantle, or in the respi- 

 ratory organs. Swammerdam observed, long- 

 ago, that snails are evidently affected by odours ; 

 and the cuttle-fish is said to show a decided 

 aversion to strongly scented plants. 



* Ibid. vol. iii. 481 ; and iv, 254. 



t A group of laminse, closely resembling the olfactory organs 

 of Fishes, has been lately observed by Mr. Owen. 



