26 EXTINCT MONSTERS 



once they realise that such finds have what political economists 

 call an " exchange value," or, in other words, can be turned into 

 money, it is astonishing what zealous guardians of Nature's 

 treasures they become! For this reason collectors often find 

 what Professor Bonney calls the "silver hammer" in other 

 words, cash more effective than the steel implement they carry 

 with them. 



