# Lehre und Wehre_St. Louis Missouri_Dezember 1898_S372
# Machine transcription, uncorrected — CHI Digital Archive (demonstration)

372 Wissenschaften und Glaubensartikel.

mav only hold good for the region in which they have been made.
Theuy must not be assumed to be strictly applicable everywhere.“

So können also auch die Fossilien, selbst bei der Annahme des ob⸗
genannten Gesetzes, keinen durchgreifenden Ausschlag geben. Was thut
man nun da? Man greift zurück zu dem früheren Argument, hergenommen
aus der Schichtung und Uebereinanderlage der Steine. Unsere geologische
Autorität hatte zwar gesagt, daß sich daraus nichts Zuverlässiges erweisen
lasse. Wir haben gesehen, dasselbe gilt auch von den Fossilien. Indeß
man nimmt nun diese zwei ungewissen Potenzen zusammen und zieht dar⸗
aus seine Resultate, die dann natürlich „wissenschaftlich“ gewiß sind. Und
so wird's gemacht: „The solution'' — siehe früheres Citat — .. all
Over the world. According to the order of superposition the fossils
roHqund in à formation must be older than those in the formation
above, and younger than those in that below. This order, how-
ver, urust be first accurately détermined, for as far as regards or-
ganic structure or aftinities, there may bé no discoverable reason
WHY a particular specieés should precede or follow another. Enless,
ror éxample, we know from observation or testimony that Ryn-
Chohella pleurodon' is à shell of the Carboniferous Limestone, and
Renchonella tetrahedra' is a shell ofthe Lias, we could not. from
mere inspection of the fossils themselves, pronounée as to their
real geological position. ... For geological purposes, therefore,
and indéed for al! purposes of comparison between the faunas and
0ras 0f ditferent periods it is absolutely essential first of all to have
the order of superposition ofe strata rigorouslx determined. Unless
chis is done the most fatal mistakes man be made in palaeontolog-
ical chronology.“ (I) But when it has once been done in one typ-
Cal district, the order thus established ma be held as proved“ ()
fOr Awide region where, from paucits of sections, or from geolog-
ical disturbance the true succession of formations cannot be satis-
kactorily determined.

The order 0f superposition having héen determined in à great
Series of stratifted formations, it is found that the fossils at the bot⸗
tom areé not quite the same as those at the top of the series. As we
trace the beds upward we discover that species after species of the
Iowest platform disappears until perhaps not one of them is found.
With theé cçessationtof these older species others make their appear-
ance. These in turn are found to die out and be replaced by newer
O0rms. After patient examination of the rocks it is ascertaineéd that
everyv well marked formation is characterized by its own species or
genera“ (type fossils. Leitfossilien) or byea general assenblage or