DISTRIBUTE INSECT VARIETY. 267 



approximates that of the modern world in all save distribution. 

 The first, or Eocene, flora dates from the Cretaceous or Chalk age, 

 and, as evidenced by the London Clay drift beds at Sheppy, 

 shows fruits of fan-palms {Flabellaria) , with those of Australian 

 banksias, silver-trees, wagonbooms, whose leaves in Hampshire 

 gravel banks of similar age mingle with the fig and cinnamon. 

 In the sandstones that lie at the base of the Alps similar plants, 

 and also palms of American type, occur. This clearly indicates a 

 flora akin to that of Australia and South Africa over Palaearctic 

 areas, while the second, or Miocene, flora shows a gradual influx 

 of North American vegetation. Thus the leaf -beds of Mull and 

 those of Bovey in Devonshire, covered by widespread eruptions 

 coeval with the cliffs of Antrim and Staffa, show the prevailing 

 plants to have been sequoias, or red-woods, vines, figs, cinnamons, 

 &c. At Bovey, according to Prof. Heer, the woods that covered 

 the slopes consisted mainly of a huge pine-tree, resembling the 

 Wellingtonia of California. The leafy trees of most frequent 

 occurrence were a cinnamon and ilex oak, similar to those now 

 seen in Mexico. The evergreen figs, the custard apples, and 

 allies of the Cape jessamine, were rarer. These glossy trees were 

 festooned with vines, beside which the prickly rotary palm 

 twined its snake-like form. In the shade of the forest throve 

 numerous ferns, one species of which shot up into trees of 

 imposing grandeur ; and there were masses of underwood belong- 

 ing to various species of Ni/ssa, like the tupelos and sour-gums of 

 North America. At (Eningen, on the embouchure of the Rhine 

 into the sea of Constance, a marly deposit of Miocene age eroded 

 by the stream, that indicates a former extension of the lake, has 

 furnished abundant remains of maples, plane-trees, cypress, elm, 

 and sweet-gum. Like the Carboniferous flora, the Tertiary in the 

 Miocene age attained high latitudes; thirty species of sombre 

 pine, with rustling stretches of beeches, oaks, planes, poplars, 

 maples, walnuts, limes, magnolias, and vines, extended northward 

 to Greenland, and there left their remains in beds of sand, clay, 

 and peat. Similar plants are found in Spitzbergen lignite strata 

 in Lat. 78'' 56', testifying to a large amount'of heat and light, 

 with mild winters for the evergreens. 



The migration and change that closed this genial epoch 

 when swarms of Tijjula and gnats hummed around the incense 



