248 ANIMAL LIFE PAST AND PRESENT. 



thoughtful and unbiassed mind. The following in- 

 stance will, perhaps, serve to illustrate this point more 

 fully. All of us are aware that paddle-wheel steam- 

 vessels were in use long before those propelled by a 

 screw were invented. Now if a naval architect had 

 to alter a paddle-steamer into one driven by a screw, 

 we should not be surprised to detect in the altered 

 vessel traces of the foundations of the paddle-boxes, 

 or part of the axle that once turned the paddle-wheels. 

 If, however, this architect were ordered to construct 

 a screw-steamer new from keel to deck, and actually 

 went out of his way to build the foundations of 

 paddle-boxes, and the ends of the axle for paddle- 

 wheels, which were not only ugly and absolutely use- 

 less, but also an actual impediment to the free use 

 and working of the ship, no one would have a moment's 

 hesitation in declaring that such a man was utterly 

 unfit for his business. 



THE END. 



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