SEXUAL SELECTION. 
Pari' II 
In the higher crustaceans the anterior legs form a 
pair of chelae or pincers, and these are generally 
larger in the male than in the female. In many species 
the chelae on the opposite sides of the body are of 
unequal size, tie right-hand one being, as I am iu" 
UR— The artist by mistake hus reversed the drawing, and made the left-hand chr |11 
thp largest. 
Hg. 5. Second leg of male Orchestiu Tucuratinga (from Fritz Muller). 
Fig. 6. Ditto of female. 
formed by Mr. 0. Spence Bate, generally, though 
invariably, the largest. This inequality is often much 
greater in the male than in the female. The two cheh e 
also often differ in structure (figs. 4 and 5, b'), the small® 1 ' 
one resembling that of the female. What advantage 
