New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1875-06-25

RELATION BETWEEN The MODERN AND TERTIARY
FLORAs.-A communication was made to the Vienna
Academy by Ettngshansen, embodying his extensive
researches on tertiary plantfossils and their study
in connection with modern ioras. Regarding the
present vegetable world the result of a former
preparatory condition, he proceeds upon the fact
that the modern horas already prctgred in the
tertiary fora, not confined, however, at present
to different distinct regions but that plants at
present denizens of widely different portions of the
earth then GOurshCd in the same region. The state
of preservation of the tosslIs Of temperate and sub
tropical plants often occurring even III the same
piece of rock renders this fact mex plicable the
hypothesis of the nngllng of the lor,s of mountains
and luwantls, aud leaves only the conclusion that
these plants honrishod in Immediate proximity.
Hence the tertiary fora, in comparison with the
ruodern NAV be regarded "a kind of compounded
primitive flora, which by resolving, it We're,
into its Clements produced the present natural
llOras, each of which consists Of a principal
element, and TO greater or less degree
of secondary elements the term element
being understood to include all geological plant
forms. the analOgues of which at present belong
clusively TO the region Of one natural flora. The
tertiary fora, therefore, it involved all modern
iOras, far of the same character over the
whole earth: In the present flora then regarded a.
the fully developed tertiary fora, there Of
course plaDt-foIms on which the impress OF the
original elements may be recognized although more
less altered. THIS Is very evident III regard To the
principal elements. but the effect of secondary ele
be inferred from the relationship of many modern
genera and species well as from their distribution
and components of the natural 1Orls, which do NOT
10 conform to the character of the same clearly
betray their association with compOnens of the See
Ondary elements; aud the more or less extensive
groups of apparently exotic plants that some
times met with in some regions only 10 be eX-
planned rs the residua Of secondary elements. Ex-
amplcs Of the extent 10 which the composite charac-
ter of the tertiary flora has still been retained in
some regions are found in Japan, the Southern por
tons of North America, and California, where plants
related t. those of almost all other regions occur.
He sums up his conclusions follows: |. The natu-
raj loras Of the world allied To each other by the
elements of the tertiary fora; 2. The character Of
natural fora is determined by the predominant de-
velopnent OF one floral element the principal ee-
mentl 3 Secondary elements have also affected the
composition of modern horas, according To climatic
conditions. The iuteTmixture of members of the
vegetable kingdom, apparently foreign To the char
acter of the hora produced III this way sometimes
appears only subordinate, but Others IL Of such an
exont that il decidedly affects the character of the
fora a. The species replacing each other in the re-
gions Of the different modern oras are corresponding
members IL similar elements.