28 ENTOMOLOGY. 



nerve ends on the surface, and is thus accessible to direct 

 chemical stimulation, while the parts can be washed with 

 the saliva. The supply of hooks and bristles on the skin 

 partly retains the saliva for cleansing purposes/and partly 

 defends the delicate ending of the nerves. All these pits 

 and goblets are situated where they come in direct contact 

 with the food. Forel, basing his opinions on the observa- 

 tions of different anatomists as well as his own, thinks that 

 the organs of taste occur in the proboscis of flies; in the 

 maxillae, and in the end of the tongue, of ants; and in the 

 palate or epipharyux of bees and beetles. 



While most insects appear to be deaf, certain organs which 

 are generally considered to be ears are well developed in 

 the locust, and we think that the sense of hearing must be 

 present, not only from the fact that a loud alarum with 

 kettles and pans affects them, but because the movements 

 of persons walking through the grass invariably disturb 

 them. Besides this, they produce a fiddling or stridulating 

 sound by rubbing their hind legs against their folded wing- 

 covers, and this noise is a sexual sound, evidently heard 

 and appreciated by individuals of the other sex. Any insect 

 which produces a sound must be supposed to have ears to 

 hear the sound produced by others of its species. 



The ears (or auditory sacs) of the locust* are situated, one 

 on each side, on the basal joint of the abdomen, just be- 

 hind the first abdominal spiracle (Fig. 22). The apparatus 

 consists of a tense membrane, the tympanum, surrounded 

 by a horny ring (Fig. 22). " On the internal surface of this 

 membrane are two horny processes (o, u), to which is attached 



* Forel, however ("Recueil Zoologique Suisse," 1887), denies that 

 these tympanic organs are necessarily ears, and thinks that all insects 

 are deaf, with no special organs of hearing, but that sounds are heard 

 by their tactile organs, just as deaf-mutes perceive at a distance the 

 rumbling of a carriage. But he appears to overlook the fact that 

 many Crustacea, and all shrimps and crabs, as well as many mol- 

 lusks, have organs of hearing. The German anatomist Will 

 believes that insects hear only the stridulation of their own species. 

 Lubbock thinks that bees and ants are not deaf, but hear sounds so 

 shrill as to be beyond our hearing. 



