308 J. Croll—Arctic Interglacial Periods. 
Canary Islands, on the nothern slopes of the mountains, at an 
elevation of from 2,000 to 5,000 feet above the sea-level—a 
region, remarks Prof. J. Geikie, nearly always enveloped in 
steaming vapors, and exposed to heavy rains in winter. In 
that deposit is also found the common laurel, associated with 
the beech. This is not now the case, as the laurel requires 
more shade than it can find there at the present, while the beech 
has retreated to the northern flanks of the Apennines to obtain 
a cooler climate. 
of a genial, humid, and equable climate having formerly char- 
acterized Northern France. The presence of the laurel, and 
during that season, and repeated frosts, says Saporta, would 
revent it reproducing its kind. It is a mild winter rather 
n 
closely approximating, in the size and shape of its leaves an f 
fruit, to that of the tufasin the south of France, and to those 0 
Northern France were formerly mild and genial, the summers 
were certainly more humid, and probably not so hot. ‘This }S 
proved by the presence of several plants in the tufa of La-Cels 
which cannot endure a hot arid climate, but abound in the shady 
woods of Northern France and Germany.” one 
The plants found in the tufas of Canstadt are much eitnilet | 
to those of Moret. Mr. Howorth, in regard to the deposits 0 
those places, says: “The coexistence of the species found there 
