50 THE PAST CONDITION 



the rest. Among the mammalia and birds there are 

 none extinct ; but when we come to the reptiles there 

 is a most wonderful thing : out of the eight orders, or 

 thereabouts, which you can make among reptiles, one- 

 half are extinct. These diagrams of the plesiosaurus, 

 the ichthyosaurus, the pterodactyle, give you a notion of 

 some of these extinct reptiles. And here is a cast of the 

 pterodactyle and bones of the ichthyosaurus and the 

 plesiosaurus, just as fresh as if it had been recently dug 

 up in a churchyard. Thus, in the reptile class, there 

 are no less than half of the orders which are absolutely 

 extinct. If we turn to the Amphibia, there was one 

 extinct order, the Labyrinthodonts, typified by the 

 large salamander-like beast shown in this diagram. 



No order of fishes is known to be extinct. Every 

 fish that we find in the strata — to which I have been 

 referring — can be identified and placed in one of the 

 orders which exist at the present day. There is not 

 known to be a single ordinal form of insect extinct. 

 There are only two orders extinct among the Crustacea. 

 There is not known to be an extinct order of these 

 creatures, the parasitic and other worms ; but there 

 are two, not to say three, absolutely extinct orders of 

 this class, the Echinodeymata ; out of all the orders of 

 the Ccelenterata and Protozoa only one, the Rugose 

 Corals. 



So that, you see, out of somewhere about 120 orders 

 of animals, taking them altogether, you will not, at 

 the outside estimate, find above ten or a dozen extinct. 

 Summing up all the order of animals which have left 

 remains behind them, you will not find above ten or 

 a dozen which cannot be arranged with those of the 



