162 J. S. Gardner — On Ettingshausen' s Theory. 
Glancing at tke distinctive Flora of tlie Californian coast-line, 
we see a series of European genera (altkougk represented by other 
species), wliose origin Ettingshausen states to kave been derived, in 
Tertiary tiines, from European elements, wkick elements, being 
universally distributed, were, kowever, according to tke Baron’s 
theory, also present even at tbat time in California. As instances, 
be traces tke Californian Quercus Douglasii and Q. agrifolia to tbeir 
supposed ancestor. The greater tke resemblance between different 
species, tke greater tke probability tliat they are derived from a 
common stock ; as, for example, we see that Liquidambar styracifluum 
and L. orientale are botk derived from tke Tertiary L. europceum, 
wkilst two other species, closely resembling eack other, L. altingia 
and L. chinense, were derived from anotker and still unknown 
ancestor. 
In tke pkyto-regions of Japan, North America, the Mediterranean, 
etc., alongside of the chief-elements tke collateral-elements kave 
also contributed tbeir skare to tke ckaracter of the Vegetation ; 
wkilst in tke temperate regions of tke Himalayas and Andes tkey 
kave markedly influenced it. On tke other band, tke Cape and 
Australian Floras owe tbeir pronounced ckaracter to a remarkably 
preponderating development of tke chief-elements, altkougk, even 
kere, residua of tke collateral-elements are to be traced. As tke 
Cape and Australian Flora-elements are, upon tkis theory, derived, 
not simply from tke European, but tke universal Tertiary Flora of 
tke temperate regions of tke world, tkey kad originally tke same 
composition. At tke Cape, plants of an Australian, and in Australia 
those of a South African ckaracter grow. Tkis theory explains tke 
Community in tke recent Floras of botk regions of a numker of 
families and genera, of wkick tke Proteaccce, Ericacem, and half a 
dozen otkers, are conspicuous examples. In other natural Floras of 
tke world remains of these elements are also met witk as represen- 
tative genera and species. Tkus in tke Mediterranean region tke 
Cape-element is seen in the Ericas, species of Mesembryanthemum, 
and a Pelargonium and Apteranthes (representing Cape Stapelice). 
Callitris, belonging to tke same Flora, is descended from an 
Australian element. Tke numerous representatives of tke existing 
Australian-element in tke Tertiary Flora of Europe do not indicate 
tkat these belong to an older type of Vegetation, but simply show 
the former connexion of these Floras tkrough tke Flora-elements, 
wken distant parts of tke globe were yet united. 
Tke Baron tken explains tkat in some regions tke Tertiary Flora- 
elements kave come down almost unckanged, and in otkers kave 
taken special characters, arising from the almost exclusive develop- 
ment of some only of tke Flora-elements, and tke expulsiou or 
suppression of tke rest. Besides tke Tertiary Floras, beds of 
Cretaceous age kave furnished plant-remains. We can trace some 
of tke Flora elements to tkis period, and prove tkat in it even simpler 
elements are contained, wkick unite in themselves some of tke parent- 
stocks, wkick we kave been considering as Tertiary Flora-elements. 
Tke differentiation of tke Flora-elements, commenced, according 
