MORPHOLOGY 245 



on the ordinary view of creation! Why should the brain 

 be inclosed in a box composed of such numerous and 

 such extraordinarily shaped pieces of bone, apparently 

 representing vertebrse ? As Owen has remarked, the 

 benefit derived from the yielding of the separate pieces 

 in the act of parturition by mammals will by no means 

 explain the same construction in the skulls of birds and 

 reptiles. Why should similar bones have been created to 

 form the wing and the leg of a bat, used as they are for 

 such totally different purposes, namely, flying and walk- 

 ing? Why should one crustacean, which has an extremely 

 complex mouth formed of many parts, consequently^ 

 always have fewer legs; or conversely, those with many 

 legs have simpler mouths? Why should the sepals, 

 petals, stamens and pistils, in each flower, though fitted 

 for such distinct purposes, be all constructed on the 

 same pattern ? 



On the theory of natural selection, we can, to a cer- 

 tain extent, answer these questions. We need not here 

 consider how the bodies of some animals first became 

 divided into a series of segments, or how they be- 

 came divided into right and left sides, with corresponding 

 organs, for such questions are almost beyond investiga- 

 tion. It is, however, probable that some serial structures 

 are the result of cells multiplying by division, entailing 

 the multiplication of the parts developed from such cells. 

 It must suffice for our purpose to bear in mind that an 

 indefinite repetition of the same part or organ is the 

 common characteristic, as Owen has remarked, of all low 

 or little specialized forms; therefore the unknown pro- 

 genitor of the Vertebra ta probably possessed many verte- 

 brae; the unknown progenitor of the Articulata, many 



