Annulate Animals to their Economy. ] 25 



the segments; whilst, in the males, the wing-bearing segments 

 are both increased in magnitude and altered in form. By 

 dissection we find that those muscles which, in the males, are 

 essential to move and guide, with great power and rapidity, 

 the organs of flight, are become obsolete, or rather repose in a 

 quiescent and undeveloped state, in the inactive females, 

 which are doomed never to traverse the realms of air. Ob- 

 serve, again, the common ant. Compare, in a winged ant, 

 the wing-bearing segments with the same parts in a worker 

 which is constantly without wings, and you cannot fail to 

 be struck with the difference in their size. In autumn, 

 large wingless ants are not uncommonly seen w^ith the wing- 

 bearing segments precisely similar to that of the winged ants: 

 these are females which have once possessed wings, but 

 which have, on settling down to form a new colony, stripped 

 off these organs as useless in the subterranean life they are 

 about to lead. 



We must, however, in making a law for the appropriation 

 of muscular developement to the extent, strength, or activity 

 of the organs it has to govern, be ever on the watch for the 

 operation of yet more positive and unvarying laws, which 

 may supersede the operation of the one we may assume. 

 Specific gravity is one of these. The lobster, which is so 

 nearly equal in weight to its own bulk of salt water that it 

 floats in it with perfect ease, can, in that medium, move its 

 ponderous claws with the greatest activity ; but in the air, 

 unless the governing muscles, and consequently that portion 

 of the body which they occupy, were increased at least ten- 

 fold in magnitude, these claws would be unwieldy and useless. 

 If we hold a lobster up by the back, we find that these claws 

 are too heavy to be employed : the forceps will pinch, and 

 that severely, but the object must be placed purposely in 

 their way. the animal possessing no muscles which will raise 

 them sufficiently to seize an object on a level with its head. 

 Still we must not conclude that the annulates inhabiting 

 water are invariably thus unfitted for exertion in another 

 medium; for this is by no means the case; many possess a 

 form and organs equally adapted for living in the water or on 

 the land. 



X2. 

 January 16. 1834-. 



(To be continued.') ^ 



