x AUTHOR Si) PRE ACE 
has, from age to age, been enacted on the terrestrial stage, of 
which we behold the latest, but probably not the closing scenes. 
When our poet wrote “ All the world’s a stage,” he thought 
only of “men and women,” whom he called “merely players,” 
but the geologist sees a wider application of these words, as he 
reviews the drama of past life on the globe, and finds that 
animals, too, have had “their exits and their entrances;” nay, 
more, “the strange eventful history” of a human life, sketched 
by the master-hand, might well be chosen to illustrate the birth 
and growth of the tree of life, the development of which we 
shall trace briefly from time to time, as we proceed on our 
survey of the larger and more wonderful animals that flourished 
in bygone times. 
We might even make out a “seven ages” of the world, in 
each of which some peculiar form of life stood out prominently, 
but such a scheme would be artificial. 
There is a wealth of material for reconstructing the past 
that is simply bewildering; and yet little has been done to 
bring before the public the strange creatures that have perished.! 
To the writer it is a matter of astonishment that the 
discoveries of Marsh, Cope, Leidy, and others in America, not 
to mention some important European discoveries, should have 
attracted so little notice in this country. In the far and wild 
West a host of strange reptiles and quadrupeds have been un- 
earthed from their rocky sepulchres, often of incredibly huge 
1 Figuier’s World before the Deluge is hardly a trustworthy book, and is 
often not up to date. The restorations also are misleading. Nicholson’s 
Life-History of the Earth is a student’s book. Messrs. Cassells’ Our Harth 
and its Story deals with the whole of geology, and so is too diffusive ; its ideal 
landscapes and restorations leave much to be desired. H.R. Knipe’s Nebula to 
Man contains a large number of beautiful restorations and landscapes. See also 
Sir E. Ray Lankester’s Hatinct Animals, 
