180 
ISLAND LIFE. 
[part I. 
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 .. 1 
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 between 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 mollusca and the higher 
animals of the two periods. It seems probable, therefore, that 
these Lower Cretaceous plants represent local peculiarities of 
vegetation such as now sometimes occur in tropical countries. 
On sandy or coralline islands in the Malay Archipelago there 
will often be found a vegetation consisting almost wholly of 
cycads, pandani, and palms, while a few miles off, on moderately 
elevated land, not a single specimen of either of these families 
may be seen, but a dense forest of dicotyledonous trees covering 
the whole country. A lowland vegetation, such as that above 
described, might be destroyed and its remains preserved by a 
slight depression, allowing it to be covered up by the detritus of 
some adjacent river, while not only would the subsidence of 
high land be a less frequent occurrence, but when it did occur 
the steep banks would be undermined by the waves, and the 
trees falling down would be floated away, and would either be 
cast on some distant shore or slowly decay on the surface or in 
the depths of the ocean. 
From the remarkable series of facts now briefly summarized, 
we learn, that whenever plant-remains have been discovered 
within the Arctic regions, either in Tertiary or Cretaceous 
deposits, they show that the climate was one capable of support- 
ing a rich vegetation of trees, shrubs, and herbaceous plants, 
similar in general character to that which prevailed in the tem- 
perate zone at the same periods, but showing the influence of 
a less congenial climate. These deposits belong to at least four 
1 The preceding account is mostly derived from Professor Heer’s great 
work Flora Fossilis Arctica. 
