New-York tribune. [volume] (New York [N.Y.]) 1866-1924, 1879-09-06

most part, under new specific forms. OF
the several Radiaie tribes lthe CnnIds. CystidS
PoIyp-ccrals etc.D substantially the same may be
said in this respect Of the Brachi0pods and even
the soonges. though On a more restricted scale.
Illustrate in their successonal history the same fact
or principle. But there Is good evidence thit
any SuriGn genera or species derived from
other genera or species.
N.-GENERAL oBsFRYATIONs.
Putting. now. all the facts together. we find in
favor OF the development theory ~ That with the
progress o; SiIuran time there WIS a rise in the
grade If Ifc the 1rilobtes probably near tie Pby
lopods m systematic positionD having added TO
their hOrdes, in the later Siluriln prob
ably higher order in Che way of the Eu,vo-
fcrBs group; the PhyllOpods and Osfraeoid,
attaining Mt or toward the close of the age
their highest expression; Cephaopods the highest
Molinslxs. being added in the Canadian period To
Gasterpods. Pteropods and Brachiopods G'rimordial
cassesl. and Cnpids ranking above the Cystids sp-
pearing after the latter in time. OF not until the
Canadian period to which may be added the intro
ducton OF Vertebrates in the later Upper Silurian;
And 81 that throughout Siluran time new genera
and species almost constantly appearing and
further that many Of thc genera and species are
closely allied hut beyond this the corroborative
evidence does not appear to extend.
the facts in opposition 10 the theory that all
Slnrian forms have been derived from a common
Drc-prmonlisl ancestor through the operations Of
the laws of nature, are, the contrary. not only
numerous, but apparently Insurmouniable. Ia the
first place, such fine 0radations exist among gen.
aud species rs should expect 10 meet with on
this theory while the staoIhty Of certain generic
types rs well ~ of certain specific forms through
enormous periods of time, positive fact bearing
ipt ba of ofcr ho
prlmordal molluscan genera Lingala and Die
Gina and the almost equally ancient Lower
Silurian genera NAUTILUS. MyHchoHeliG, CroHia and
Picm0tOmdria still continue To exist in our own
seas; while q number of othor Lower Sllnrian
genera extend through the whole Paleozoic SERIES
and certain species through several periods, OF an
entire system of rocks.
Again, the order ~ well as manner of introduce
ton Of the yarions classes and tribes Of the Surian
is widely 1T variance with the requirements Of this
theory. If the earth has been stocked with living
forms in the way supposes should expect to ind
in the lowest Primorlal beds first, Sea-weeds then
Sponges and other PrctozOans; next, Polyp-corals
aud Acalcphs with, later on. Cystids and Crinids;
next. Bryozoans. Brachiopods, Acepha.a, Pteropods
GasteropOds aud Cephalopods; and lastly, Phyllo-
pods, Ostracods ard Tubohtes the specie, decrees-
m number from tho Spongcs upward througn the
seen in article 2, give a contrary rendering
and show that the Cystds preceded the Polyp-.
corais: that the Brachopods preceded he Lameili-
branchs or A-ephaia, as. however, on Tins theory
they should have done although accompanied, at
the outset, by both PterOpods and Gasteropods.
classe, above the Acephala in geological rank;
AID that the Tiiooites aud other Crusia-
ccans antcdaied both the Cephaopods and Laulel,i-
hranchs. and even the Crinias. these lattcr n
have before observed not appearing until the next
period. Furthermore. the number Of species Of
Pumordia Irilobitcs is many fold greater than that
of all the other Glasses of the period.
| will now add few words upon the manner Of
appearance of the classes and tribes under notice,
and with these bring my observations 10 close. In
the lowest beds In which Tlobics are found at all.
we meet with forms having nearly the greatest
number of body-segments known IN the tribe. along
with those possessing the smallest number; with
forms of gigantic As well OF dIminutye proper
tons: and with rich and varied display Of generic
types. As l have pointed ont in my second
article, they do not appear at all m the lowest
Primordial rocks, but, higher up. come suddenly
upon the scene fu-auned and full-hedged and
without the exhibition Of any premonitory
symptoms on the part of the earlier Sponge. Bra
chopods OF PteIopods. far as we can discover OF
their coming. The CcphalOpOds, Accplaia. Crinids
and lOypS make tlcli lfsl appearance III lnc rdic
quiet aud unexpected way, and the same Is true Of
the En- -ypterids and Fishes. In my Judgment the
,ransnutaion theory fails 10 account for these
facts and if animals possess or have ever possessed
or are surrounded or have ever been surrounded By
any force power competent, in the course Of ages
to evolve an UTih0csras out of Orlhis. a GdR0h
out OF Ptoygotpa. such force power remains TO
be discovered The abrupt changes of form that are
known 10 occur among certain animals in their
larval or embryonic state. have been put forward IS
ahorling a probable explanation of The mode OF
origin of Slurian types but the facts Of silurian
life furnish no evidence of this, and few think'
will be prepared TO believe that the adult lie Of the
Siiuiian world was IN that universally embryonic
condition. which the adoption of this mode OF ex-
panatiOn would require rs TO assume Ito have been.
In view of the whole case il seems TO mo as though
the display Of Siluran life hal taken place IN
accordance with a definite plan, and under The I'M
mediate supervision OF an intelligent Author ana
Ordaiher, whose work 1t Is.
With tho above remarks | shall conclude my
sketch Of the Life of the s;iiurln Age though not
without regret but If any Of my readers shouldbs
led By rejecting upon Oh" 'scts presented, 10 study
for the first time, IT Ms deeply. the wonderful
record itself of which h endeayored to give
tolerably comprehensive though necessarily upper
feet account IN the present series of articles, the
WRITER will feel that some good has been accom-
pshed. and that he has labored not wholly IN Valn
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