94 W. WESCHB ON SOME NEW SENSE-ORGANS IN DIPTERA. 



I therefore conclude that all these structures in Blatta, Ajris, 

 Vespa, Paaorpa, and Musca are " taste hairs" and homologous, and 

 that Will's "taste cups " are misnamed, being only modifications 

 of the characteristic hair. 



One can now say that the sense of taste in insects is conveyed 

 l>y a blunt, hollow, rather characteristic peg or hair, which may 

 be (1) scarcely showing, as in Will's organ; (2) longer, as in 

 the structures on the maxillae of V. crabro and the labium of 

 some Dipteia ; (3) nearly double the length of the socket, as 

 on the discs of the labium of V. vulgaris and V. crabro. This 

 hair is loosely fixed in the socket and rather long when on 

 the labium of the Hymenoptera, but shorter when on other 

 parts, and in Diptera. The socket may be quite long, as in the 

 labium of Vespa, shorter but still evident, as in the Muscidae, or 

 only perceptible, or even sunk to the level of the epidermis, as 

 on the maxilla of Vespa. This is but an amplification of Lord 

 Avebury's able generalisation when he concludes, " that the 

 organs of taste in insects are certain modified hairs, situated 

 either in the mouth itself, or on the organs immediately 

 surrounding it." * 



There is a conflict of opinion on the subject of hearing, for 

 though some tympanic organs in stridulating insects, such as 

 locusts or crickets, have been thought to be auditory organs, Forel,f 

 whose opinion has much weight, denies that these tympanic 

 organs are necessarily ears, and thinks that all insects, possess 

 no special organ of hearing, but that sounds are perceived 

 by their tactile organs, just as deaf mutes can detect at a dis- 

 tance the rumbling of a carriage. If this opinion is correct, all 

 insects would hear, as all can feel, and it has been demonstrated 

 that some insects, if not the majority, are, as far as can be 

 ascertained by experiment, quite deaf. 



What we know about the Culicidae (Gnats) agrees with M. 

 Forel's idea. The hairs on the antennae of the males vibrate 

 •sympathetically if a tuning fork, giving a note near to that of the 

 " pipe " of the female, is sounded near them. On the other hand, 

 a number of experienced entomologists, have separately come to 

 the conclusion that auditory organs exist in the antennae of 

 many species, and the deep pits or cavities in the antennae 



* Senses of Annuals, p. 31. 



f Recueil Zoologique Suisse, 1887. 



