XI PHENOMENA OF ORGANIC NATURE 355 



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 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 present day ; 

 that is to say, that the difference does not amount 

 to much more than ten per cent. : and the 

 proportion of extinct orders of plants is still 

 smaller. I think that that is a very astounding 

 a most astonishing fact : seeing the enormous 

 epochs of time which have elapsed during the 

 constitution of the surface of the earth as it at 

 present exists, it is, indeed, a most astounding 

 thing that the proportion of extinct ordinal types 

 should be so exceedingly small. 



But now, there is another point of view in which 



