PRESIDENT’S ADDRESS. Sole. 
solution of the problem of the origin of life ; for even if chemists* 
should show us how protein might be formed under the con- 
ditions just indicated, the important gap between dead protein 
and the simplest living protoplasm would still remain to be bridged. 
Nevertheless, we certainly have a clearer idea than we had before 
of the problem which has to be solved; and that is a step in 
advance. It is, indeed, the only step that can be taken by geolo- 
gists. 
ORDOVICIAN AND SILURIAN LIFE. 
I will now pass on to glance at the life of the Ordovician and 
Silurian periods. The Ordovician was ushered in by the appear- 
ance of the highest sub-kingdom of animals, the vertebrata, repre- 
presented by minute teeth, called conodonts, from the green sands 
at the base of the Ordovician, near St. Petersburg. Fossils called 
conodonts have been found in various places, and in rocks of 
different ages, from the Upper Cambrian to the Carboniferous, but 
they differ much from one another. Some are, no doubt, the jaws 
of Chetopod worms; others are thought to be of crustacean origin, 
although no explanation is given of why these crustacean jaws 
should always be found dissociated from the other parts of the exo- 
skeleton; possibly some may belong to Cephalopoda ; but the cono- 
donts, just mentioned, from St. Petersburg, have been shown by 
Dr. J. von Rohon to have enamel and dentine, with a pulp-cavity 
of an essentially vertebrate character, and this has been confirmed 
by Dr. Otto Jaekel; so that in all probability they belonged to 
lamprey-like animals, and if this is the case paleontology offers 
no support to Dr. Gaskell’s ingenious hypothesis that the verte- 
brates are descended from the Merostomata. 
In the Upper Ordovician of Colorado there have been found 
plates of an ostracoderm allied to Asterolepis, and true fishes are 
represented by enamelled scales, thought to resemble those of 
Holoptychius, and therefore to belong to the Crossopterygil, as 
well as by what appears to be the ossified chordal-sheath of a 
chimeroid fish. The late Professor Cope expressed a doubt as to 
the vertebrate origin of these fossils ; but I have not been able to 
find that he has anywhere published reasons for his doubt. 
The invertebrates which first claim our attention are the Grap- 
tolites and the Brachiopods. The Graptolites are known in North 
America from the Lower Cambrian to the Carboniferous, but in 
Europe they first appear in the Upper Cambrian as a monoprioni- 
dian form allied to Dichograptus. In the lowest beds of the 
Ordovician they suddenly attain their greatest devolpment, after 
which they gradually decline, and only a few forms pass into the 
Devonian. The earlier forms had many irregular branches, which 
* Professor Liversidge informs me that some of the native mineral oils (Petroleum, 
Naphtha, etc.) contain oxidised compounds. 
