22 CHELTENHAM COLLEGE NATURAL HISTORY SOCIETY. 
and that therefore the disappearance of so many genera implies a 
long lapse of time. 
Similarly with the archeological evidence. Between the Old 
Stone age man—to whom the unpolished flint implements belonged 
—and the Historic period, come the New Stone age, the Bronze age, 
and a portion of the Iron age, and each of these probably represents 
along interval. That this is so is emphasised by the peat bogs of 
Denmark ; they prove the vegetation of the country to have changed 
three times—from pine to oaks with sessile leaves, from oaks with 
sessile leaves to others with pedunculated leaves, and finally to 
beeches, which are now the dominant race. There is evidence to 
show that the beech was already in full possession at the time of the 
Romans, so that perhaps 2,500 years may be taken as the minimum 
for the beech period ; and so with the oak and pine periods, yet not 
a trace of any extinct animal has been found even at the bottom of 
the pine deposit of the peat bog ; and it takes us back at the most 
to the limit of the New Stone age—ze., to the period subsequent to 
the cave earth deposit of Brixham and Kent’s caves. 
Mr. Hichens also discussed the theories that have been put 
forward in explanation of the Ice age. Man seems to have been 
at least Glacial, and some people consider that there is sufficient 
evidence to justify the belief that he was pre-Glacial. On Croll’s 
theory the Glacial period in England died away not less than 80,000 
years ago. Soit is with regard to the changes that have taken place 
in physical geography since man’s first appearance. Implements are 
to be found in river gravels as much as 200ft. above the present level 
of the river, and every known fact goes to show that the rate at 
which a stream cuts its way to a lower level is extremely slow. 
Wherever we look—whether we consider the cave deposits 
themselves, or the changes that have taken place in the animal life, 
or the periods that come in between the Old Stone age and our 
own time, or the probable date of the Glacial period, or the alter- 
ations in physical geography—everything points to the same con- 
clusion, that the time since man’s first appearance on the earth is 
to be numbered by many thousands rather than hundreds of years. 
On May 2oth Mr. Hichens gave a Lecture on “ Life in the 
Primary Period,” illustrated by Fossils from the Museum, and 
by Lantern Slides. 
