BIG ANIMALS 265 



during which the different species were gradually demar- 

 cated from one another. 



Some of the ammonites, which belonged to this cuttle- 

 fish group, soon attained a very considerable size ; but a 

 shell known as the orthoceras (I wish my subject didn't 

 compel me to use such very long words, but I am not per- 

 sonally answerable, thank heaven, for the vagaries of 

 modern scientific nomenclature) grew to a bigger size than 

 that of any other fossil mollusk, sometimes measuring as 

 much as six feet in total length. At what date the gigantic 

 cuttles of the present day first began to make their appear- 

 ance it would be hard to say, for their shell-less bodies are 

 so soft that they could leave hardly anything behind in a 

 fossil state ; but the largest known cuttle, measured by Mr. 

 Gabriel, of Newfoundland, was eighty feet in length, 

 including the long arms. 



These cuttles are the only invertebrates at all in the 

 running so far as colossal size is concerned, and it will be 

 observed that here the largest modern specimen immeasur- 

 ably beats the largest fossil form of the same type. I do 

 not say that there were not fossil forms quite as big as the 

 gigantic calamaries of our own time on the contrary, I 

 believe there were ; but if we go by the record alone we 

 must confess that, in the matter of invertebrates at least, 

 the balance of size is all in favour of our own period. 



The vertebrates first make their appearance, in the 

 shape of fishes, towards the close of the Silurian period, 

 the second of the great geological epochs. The earliest 

 fish appear to have been small, elongated, eel-like creatures, 

 closely resembling the lampreys in structure ; but they 

 rapidly developed in size and variety, and soon became the 

 ruling race in the waters of the ocean, where they main- 

 tained their supremacy till the rise of the great secondary 

 saurians. Even then, in spite of the severe competition 



