PLIOCENE PERIOD 
But they, though fathers of giraffes to be, 
Not yet from Elk and Antelope are free. 
Old-time rhinoceroses still roam about, 
But hornless forms seem well nigh weeded out. 100 
And thick-jawed brutes, on Grecia's plains that feed, 
May prove the sires of Afric's long-horned breed. 
The Dinotheria named, those quaint trunked brutes 
That with their downcurved tusks tore up the roots 
Of plants in stream and lake, still hold their own ; 105 
And some indeed gigantic brutes have grown. 
Piping must one suppose their times to be, 
If size bears witness to prosperity. 
Yet now looms near the ending of their line, 
And this their climax prophesies decline. 1 10 
Perchance o'erfilled with good things in their day 
Abundant food and ease oft spell decay 
They fat are waxed, and are as Jews become 
That wailing Jeremiah warned of doom. 
The Mastodons, that in their teeth draw more 1 1 5 
To elephants, have longer days in store. 
Large forms now here seem well upon the way 
To elephants true formed of later day. 
And though four-tusked most creatures still appear, 
Short are the tusks their underjaws now bear. 1 20 
And some there are, from whose shrunk lower jaw 
'S3 
