RESULTS OF PAL^ONTOLOGICAL RESEARCH 61 



period. f These new plants, almost from the very 

 commencement, appear in such quantities that the 

 Gymnosperms, which earlier predominated, to say 

 nothing at all of the Ferns, etc., had to retreat to the 

 background/ l 



The classification of the separate families depends 

 upon the leaves, which in most cases naturally cannot 

 secure absolute certainty. Stems are rare and the 

 flowers we know really only by enclosures in amber. 

 The Catkin-bearers and the Laurel family are in any 

 case very old groups. Since the Oligocene period 

 we find, in ever greater numbers, specie's similar 

 to or quite like the present ones, and often quite 

 ' specialized/ In the Pliocene there already lived, for 

 example, the Silver Poplar, the Aspen, the Red Beech, 

 the Mountain Maple, etc. 



Conclusions from 1. 



(1) The earliest history of the plant world is so far 

 entirely unknown to us ; we know neither when the 

 first growths appeared, nor how they looked. 



(2) It must be accepted that already, at the time 

 when the Cambrian and pre-Cambrian formations 

 were deposited and the animal world was already so 

 grandly developed, a rich flora of some kind also 

 existed, since the animal world is dependent upon the 

 plant world. 



(3) Despite the great imperfection of the evidence 

 obtained, and the fact that it is only remains of 



1 Gothan : Entwicklung der Pflanzenwelt, p. 86. 



