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the Jimbs separately and combined, and interspersed several detached 

 remarks raade at various times during our studies formerly, and by some 

 additions brought them into something like a methodical arrangement 

 where none before existed, so we hope they may serve as an imperfect 

 beginning or basis for receiving more fully digested views, and stiniulate 

 others to the farther prosecution of the subject. We now conclude our 

 labours in this way with one remark more respecting the moving powers 

 of the limbs, and their distribution to effect the great object of progres- 

 sion, which has appeared to us not to be merely obtained by the flexor 

 and extensor muscles, but is contributed to, if not chiefly caused, in 

 several instances at least, by what have been called the abductor and 

 adductor muscles : for it may be seen on examination, that in the upper 

 parts of the extremities a four-fold position of the muscles is provided, 

 being placed before, behind, and on either side the limb, the two former 

 bending and extending the limb directly have been called the extensors and 

 ßexors, those on the sides drawing the bona to the outside or inside 

 according to their Situation, considered singly, have been called abductors 

 and adduclors, or, as they bring the limb towards or carry it from the 

 body ; these latter, we believe, can be made essentially to co-operate in 

 the Progression of the animal, in the following manner, viz. by contracting 

 or acting at the same moment of time on both sides the limb, which, if 

 with nearly equal forces, the bone will not in this case be drawn in either 

 of those directions, but will be compelled to take a course in the diagonal, 

 or at right angles to these, in the direction of the flexors and extensors, 

 with great power, describing a somewhat similar line that a stick would, 

 placed against a wall at one end and drawn by two cords at the other with 

 nearly equal force, it would not long remain stationary, but pass in a per- 

 pendicular line between the two opposing cords, and describe a portion of a 

 circle perpendicularly between them ; in this, or some similar way, these 

 muscles could be of constant use, otherwise the largest and most powerful 

 muscles in both extremities would appear to be almost idle masscs orflesh, 

 and truly idle offices have been assigned them, as turning out the limb 

 a little, or inwards a little, or grasping bodies, for which the animal can 

 have no occasion, steadying the body, &c. conclusions drawn from insulated 



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