186 



ISLAND LIFE 



PART I 



the dicotyledons the genera Populus, Myrica, Ficus, Sassa- 

 fras, Andromeda, Diospyros, Myrsine, Panax, as well as 

 magnolias, myrtles, and leguminosse. Several of these 

 groups occur also in the much richer deposits of the same 

 age in North America and Central Europe ; but all of 

 them evidentl}^ afford such fragmentary records of the 

 actual flora of the period, that it is impossible to say that 

 any genus found in one locality was absent from the other 

 merely because it has not yet been found there. On the 

 whole, there seems to be less difference between the floras 

 of Arctic and temperate latitudes in Upper Cretaceous 

 than in Miocene times. 



In the same locality in Greenland (70° 33' N. Lat. and 

 52° W. Long.), and also in Spitzbergen, a more ancient 

 flora, of Lower Cretaceous age, has been found ; but it 

 differs widely from the other in the great abundance of 

 cycads and conifers and the scarcity of exogens, which 

 latter are represented by a single poplar. Of the thirty- 

 eight ferns, fifteen belong to the genus Gleichenia now 

 almost entirely tropical. There are four genera of cycads, 

 and three extinct genera of conifers, besides Glyptos- 

 trobus and Torreya now found only in China and Cali- 

 fornia, six species of true pines, and five of the genus 

 Sequoia, one of which occurs also in Spitzbergen. The 

 European deposits of the same age closely agree with 

 these in their general character, conifers, cycads, and ferns 

 forming the mass of the vegetation, while exogens are 

 entirely absent, the above-named Greenland poplar being 

 the oldest known dicotyledonous plant.^ 



If we take these facts as really representing the flora of 

 the period, we shall be forced to conclude that, measured 

 by the change effected in its plants, the lapse of time be- 

 tween the Lower and Upper Cretaceous deposits was far 

 greater than between the Upper Cretaceous and the 

 Miocene — a conclusion quite opposed to the indications 

 afforded by the moUusca and the higher animals of the 

 two periods. It seems probable, therefore, that these 

 Lower Cretaceous plants represent local peculiarities of 



1 The preceding account is mostly derived from Professor Heer's great 

 work Flora Fossilis Arctica. 



