LAMELLICORNIA. 6 



(excepting one remarkable genus Pleocoma) having eleven joints 

 to the antenna ; though this is the normal number in most other 

 Coleoptera. 



The basal joint oE the antenna is generally considerably larger 

 than the rest, the second globular, and those intervening between 

 that and the club small and one or two of them sometimes wanting. 

 The antennae are always ])laced far apart, immediately in front of 

 the eyes, and beneath a ridge or brow which divides the eye in 

 front and is absent only in the genus Ochodceus. 



The form of these organs indicates that they are no longer 

 tactile as in so many other insects. Various arguments have 

 been used to show that the sense either of smell or of hearing is 

 located in the antenna of beetles, and it seems likely that tliis 

 highly developed organ of the Lamellicornia is the seat of botli 

 these senses, if anything really similar to the auditory sense of 

 higher animals occurs in insects. Of this faculty we know little, 

 but vocal organs are common although not general. There is little 

 doubt, however, that an olfactory sense is universal and highly 

 developed. M. Fabre has found that Bolhoceras is able to locate 

 truffles hidden below the ground, as pigs or dogs can do, but with 

 still greater precision. He observed that the beetles would fly 

 straight to a particular spot and, alighting, tunnel immediately 

 downwards, and that beneath that spot a truffle, the natural food 

 of the species, was invariably found. The antennae frequently 

 differ in the degree of development in the two sexes and, when 

 this is so, they are always more highly developed in the male than 

 in the female. The highest pitch of perfection is found in males 

 the females of which are rather inert and degenerate, but there can 

 benodoubt that the individualsof a species areable to find each other 

 by means of an almost inconceivably delicate olfactory sense and 

 that this sense is located in the antennae. It is a familiar fact 

 that the males of certain moths, the antennae of which are pectinate 

 (comb-like), while the females are inactive, are attracted from 

 considerable distances to the latter, even when they are enclosed 

 in dark boxes. Certain Lamellicorn beetles (e. g. Pachypus, 

 Clitopa) have wingless females, which live beneath the ground 

 and similarly attract the males, which fly in swarms to their 

 burrows ; and it is interesting to find that in these insects also 

 the antennas of the males are of the most highly lamellate type, 

 while those of the females, like those of the female moths, are 

 much simpler. That the means of attraction is a scent is shown by 

 an incident recorded by M. Perris in Petites Nouvelles Ento- 

 mologiques, 1874, p. 383. M. Eeveliere happened to observe in 

 Corsica numbers of male Pachypus cornutus flying in a certain 

 direction, and tracing them to their destination found the wingless 

 female about a yard below the surface of the ground. This when 

 handled squirted out a milky fluid which fell upon the sleeve of 

 his coat and also upon an insect specimen previously placed in a 

 box. Both this specimen and the coat-sleeve continued for several 

 days to attract flights of the male beetles. There are other beetles, 



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