OF ORGANIC NATURE. 51 



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 astouuding, a most astonish- 

 ing fact, seeing the enormous epochs of time vrliich 

 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 we 

 must look at this past creation. Suppose that we 

 were to sink a vertical pit through the floor beneath 

 us, and that I could succeed in making a section 

 right through in the direction of New Zealand, I 

 should find in each of the different beds through 

 which I passed the remains of animals which I should 

 find in that stratum and not in the others. First, I 

 should come upon beds of gravel or drift containing 

 the bones of large animals, such as the elephant, 

 rhinoceros, and cave tiger. Rather curious things to 

 fall across in Piccadilly ! If I should dig lower 

 still, I should come upon a bed of what we call the 

 London clay, and in this, as you will see in our galleries 

 up-stairs, are found remains of strange cattle, remains 

 of turtles, palms, and large tropical fruits ; with shell- 

 fish such as you see the like of now only in tropical 

 regions. If I went below that, I should come upon the 

 chalk, and there I should find something altogether 

 different, the remains of ichthyosauri and pterodactyles, 

 and ammonites, and so forth. 



I do not know what Mr. Godwin Austin would say 

 comes next^ but probably rocks containing more ammo- 



