282 On the Plants of the World before Man. 
exile. It is this exodus that we should have to describe if we 
could follow, step by step the march of retrogression, and indi- 
cate species by species, the progress and the result of this 
abandonment of our soil.” 
he decline in the richness of the vegetation of the Miocene 
ent American types. The Conifers are still those of the Molasse, 
to which Salisburia adianioides is added. Sassafras, [artoden- 
ica. 
rugosum, an Ilex, a Juglans, and among the ferns, Woodwardia 
radicans and Adiantum reniforme. As remarked by Saporta, 
the Poplar (Populus alba plocenica), the Button Wood, Plata- 
nus, the Magnolia and the Tulip tree in the Mio-pliocene of 
urope were about the same as the species now inhabiting 
North America; are specifically recognizable, though mark 
with slight differences. The relation of these species and others 
named by the author to some of the present time is examine 
by an exposition of the gradations which have given them their 
present characters, 
The last chapter, entitled “a general insight into the ensem- 
ble of the period,” cannot be summed up in a few sentences. 
It relates especially to the phenomena which have contributed, 
as causative agents or as elements, to the gradual modification 
Hedera, Nerium, as the PI r in successive periods from the 
Eocene to the end of the Pliocene. 
Ee ee en Oe, ne 
