104 



CERTAIN PARASITIC INSECTS. 



123. Louse of the Cat. 



arising from the back of the third." He farther remarks, that 

 "the males of this [which lives on the turkey] and all the other 

 species of Goniodes, use the first and third joints of the anten- 

 na3 with great facility, acting the part of a finger and thumb." 

 The antennae of the females are of the 

 ordinary form. This hand-like structure, 

 is, so far as we know, without a parallel 

 among insects, the antennae of the He- 

 miptera being almost uniformly filiform, 

 a'nd from two to nine-jointed. The 

 design of this structure is probably to 

 enable the male to grasp its consort and 

 also perhaps to cling to the feathers, and 

 thus give it a superiority over the weaker 

 sex in its advances towards courtship. 

 Why is this advantage possessed- by the 

 males of this genus alone? The world 

 of insects, and of animals generally 

 abounds in such instances, though exist- 

 ing in other organs, and the develop- 

 mentist dimly perceives in such departures from a normal type 

 of structure, the origin of new generic forms, whether due at 

 first to a seemingly accidental variation, 

 or, as in this instance, perhaps, to long 

 use as prehensile organs through suc- 

 cessive generations of lice having the 

 antennae slightly diverging from the 

 typical condition, until the present 

 form has been developed. Another 

 generation of naturalists will perhaps 

 unanimously agree that the Creator has 

 thus worked through secondary laws, 

 which many of the naturalists of the 

 present day are endeavoring, in a truly 

 scientific and honest spirit of inquiry, 

 to discover. 



In their claw or leg-like form these , 124 ' Louse of the Goat ' 

 male antenna also repeat in the head, the general form of the 

 legs, whose prehensile and grasping functions they assume. 

 We have seen above that the appendages of the head and tho- 

 rax are alike in the embryo, and the present case is an interest- 



