OF ORGANIC NATURE 41 



I explained what I meant by ORDERS the other day, 

 when I described the animal kingdom as being divided in 

 sub-kingdoms, classes, and orders. If you divide the 

 animal kingdom into orders, you will find that there are 

 about one hundred and twenty. The number may vary 

 on one side or the other, but this is a fair estimate. That is 

 the sum total of the orders of all the animals which we know 

 now, and which have been known in past times, and left 

 remains behind. 



Now, how many of those are absolutely extinct ? That 

 is to say, how many of these orders of animals have lived 

 at a former period of the world's history, but have at 

 present no representatives ? That is the sense in which 

 I meant to use the word " extinct." I mean that those 

 animals did live on this earth at one time, but have left 

 no one of their kind with us at the present moment. So 

 that estimating the number of extinct animals is a sort of 

 way of comparing the past creation as a whole with the 

 present as a whole. 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 ptero- 

 dactyle and bones of the ichthyosaurus and the plesio- 

 saurus, 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 Echinodermata ; 

 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 



