88 



EXTINCT MONSTERS. 



other parts, such as limb-bones, but more especially the bones of 

 which the backbone is composed (known as vertebras). These 

 are very important. The veteran anatomist, Professor Owen, has 

 said, " If I were restricted to a single specimen on which to 

 deduce the nature of an extinct animal, I should choose a 

 vertebra to work out a reptile, and a tooth in the case of a 

 mammal." Seven or eight different " characters," he says, may 

 be deduced from a reptilian vertebra. It is, of course, impossible 



FIG. 20. Tooth of Iguanodon, with the apex slightly worn. (From the 

 Wealden Beds of Tilgate Forest. Natural size.) I. Front aspect, showing 

 the longitudinal ridges and serrated margins of the crown. 2. View of the 

 back, or inner surface of the tooth, a. Serrated margins, b. Apex of the 

 crown worn by use. 



for any one to reconstruct an entire animal from a single bone or 

 a few teeth, yet such fragments indicate in a general way the 

 nature of a lost creation and its position in the animal kingdom. 



It is all the more important to give to the general reader this 

 warning, because an impression seems still to remain in the 

 popular mind that Owen could and did restore extinct types from 

 a single bone or a single tooth ; but no anatomist would attribute 

 to any mortal man such superhuman power. Let us, therefore, 



