38 Dr. J. Croll on Arctie 
at an elevation of from 2000 to 5000 feet above the sea-level— 
a region, remarks Prof. J. Geikie, nearly always enveloped in 
steaming vapours, 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 present, while the beech 
has retreated to the northern flanks of the Apennines to obtain 
a cooler climate. 
In the tufas of Provence are found groups the same as those 
which flourish there at present, but commingled with them are 
also the Canary laurel and other plants which are no longer 
natives of Provence. Saporta directs attention to the fact that 
species such as the Aleppo pine and the olive, demanding consi- 
derable summer-heat rather than a moist climate, are entirely 
wanting in the tufas. . 
Similar to those of Provence are the tufas of Montpellier. 
Saporta concludes that when all those species lived together 
the climate must necessarily have been move equable and 
humid than at present. In other words, the summers were 
not so dry and the winters were milder than they are now. 
The deposit near Moret, in the valley of the Seine, is still 
more remarkable in showing the equable condition of climate 
which then prevailed. The assemblage of plants found there 
tells a tale, says Prof. J. Geikie, which there is no possibility 
of misreading. “ Here,” he says, ‘we have the clearest 
evidence of a genial, humid, and equable climate having 
formerly characterized Northern France. The presence of 
the laurel, and that variety of it which is most susceptible 
to cold, shows us that the winters must have been mild, for 
this plant flowers during that season, and repeated frosts, 
says Saporta, would prevent it reproducing its kind. It is 
a mild winter rather than a hot summer which the laurei 
demands, and the same may be said of the fig-tree. The 
olive, on the other hand, requires prolonged summer heat to 
enable it to perform its vital functions. Saporta describes 
the fig-tree of the La-Celle tufa as closely approximating, in 
the size and shape of its leaves and fruit, to that of the tufas 
in the south of France, and to those of Asia Minor, Kur- 
distan, and Armenia. But if the winters in Northern France 
were formerly mild and genial, the summers were certainly 
more humid, and probably notso hot. ‘This is proved by the 
presence of several plants in the tufa of La Celle which 
cannot endure a hot arid climate, but abound in the shady 
woods of Northern France and Germany.” 
The plants found in the tufas of Canstadt are much similar 
to those of Moret. Mr. Howorth, in regard to the deposits of 
