352 O. C. Marsh—History and Methods of 
The fourth period in the history of Paleontology dates from 
this time, and is the period of to-day. One of the main char- 
acteristics of this epoch is the belief that al life, living and 
extinct, has been evolved from simple forms. ‘Another prom- 
inent feature is the accepted fact of the great antiquity of the 
human race. ese are quite sufficient to distinguish this 
. 
period sharply from those that preceded it. 
h 
gf Coa 
he difference between Lamarck and Darwin is essentially = 
this: Lamarck proposed the theory of Evolution; Darwin 
changed this into a doctrine, which is now guiding the inyesti- 
gations in all departments of biology. Lamarck failed to real 
ize the importance of time, and the interaction of life on 
life. Darwin, by combining these influences with those also 
suggested by Lamarck, has shown how the existing forms on 
the earth may have been derived from those of the past. 
This revolution has influenced Paleontology as extensively 
as any other department of science, and hence the new period 
are discussing, 
sented independently, by parallel lines; in the present perl 
they are indicated by dependent, branching lines. The former 
was the analytic, the latter is the synthetic, period. To-day, cond 
Imais and plants now living are believed to be genetically 
lees glpase grt ce: hele sede ee = ee Pa 
at longer deems species of the first im rtance, but seeks for 
pa and genealogies, eoanicsting the past with the 
Present. Working in this spirit, and with such a method, the 
advance during the last decade has been great, and is an earnest 
of what is yet to come. 
| The progress of Palxontology in Great Britain during the 
Present period has been great, and the general interest in the 
sucnee much extended. The views of Darwin soon found 
acceptance here. Next to his discovery of “ Natural Selectio?, 
