INTUdDICTION'. 17 



ill ■ Tile Descent ot" Man," luul iJicviously expressed liis belief 

 in suoh a eompen.satory ])roees.s as explain iiij; the disappearance 

 of horns in the C'oprid <fenus Onitis and other evidences of 

 its existences are not rare, hut Laineere's theory cannot be 

 regarded as more than a hold s})eculation. 



Male and female Li'CANri).*: may he absurdly disproportioned 

 in size, the male a giant, tlie female a dwarf, the reverse of the 

 usual condition in insects. Finally, colour and pattern may 

 be dissimilar. The male Lumnus mearesi is metaUic green 

 or bronzy, that of Hcmrt/iriiis jxirrj/i has bi-ight yellow elytra 

 with a black border ; the females of both are black. In 

 Dorcus loitubirhnji the male is brick-red in colour and the 

 female is decorated with bright yellow stripes on a black 

 backgi-ound. Dorcus fmtrio is yellow with a dark head and 

 dark stripes on thorax and elytra, its female is black with 

 3'^ellow- bordered elytra. In others, Dorcu.s sj)eciosi(.s, Calcodes 

 ruvera, deks.serti, etc., in which the elytra are in part black 

 and in part yellow, the ])roportions of the twf) colours are 

 diflferent in the two sexes. 



It is evident tliat the coirect association of the two sexes of 

 these insects may l)e difficult ; but the association of male 

 specimens of diffenMit sizes of the same sjjccies may present 

 similar difficulty, for, while female Li'Canid.-e are rather 

 constant, males are astonishingly polymorphic. If a long 

 series of examples is assembled of any species differing strongly 

 in the sexes, it will be found that those features which dis- 

 tinguish the males are exceedingly variable, being most jiro- 

 nounced in the largest and least in the smallest, with a gradual 

 transition through those of intermediate size. If, therefore, 

 the two sexes differ completely, it may be found that large 

 and small males of the same s])ecies have scarcely any external 

 character common to both. When, as has very fixHpiently 

 been the case, systematists liave dealt \\ith single specimens 

 only, they have quite naturally regarded and named the 

 different phases as different species. In Dorais rcichfi, 

 Plate II, fig. 1 , the females (fig. 1 a) have the head rough and 

 the elytra deeply grooved and bear no resemblance whatever 

 to the extremely smooth males, fig. 1 ft, well-develo])ed examples 

 of which are t\\'ice the length of even the largest females, 

 and have an enormous head with branched mandibles as long 

 as the head and thorax together. Smaller examples are less 

 smooth, the head is smaller, the jaws shorter, and the elytra 

 show traces of longitudinal dej)ressions, fig. I e. The less the 

 size the greater becomes the resemblance to the other sex, 

 until we reach tiny male specimens, fig. 1 h, one-third the 

 U'ligth of the large ones, with a small rough head, insignificant 

 mandibles and deeply grooved elytra ; there is a close resem- 

 blance to the female and none at all to the large males. An 



c 



