52 PREHISTORIC EUROPE. 



on the other hand, requires prolonged summer heat to enahle 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, Kurdistan, and Armenia. But if 

 the winters in Northern France were formerly mild and genial, 

 the summers were certainly more humid and probably not so 

 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. 

 It was, as Saporta remarks, a combination of clement winter 

 with pronounced humidity, which accounts for the association 

 at La Celle of the fig-tree, the Canary laurel, and the sycamore. 

 We may note, however, that notwithstanding the equableness 

 of the climate, the difference of latitude between Paris and Pro- 

 vence is yet clearly evinced by the flora of the tufas. Thus the 

 common ash and the sycamore, which are plentiful in the tufa 

 of La Celle, are wanting in the travertine deposits of the south, 

 where they are represented, as we have seen, by the manna-ash, 

 now only indigenous in Corsica and South Italy, and by Acer 

 opulifolinm, which has retired from the low grounds of Provence 

 and taken refuge in the hilly parts of the Mediterranean region. 

 According to Professor Crie, the flora of the travertine 

 deposits of Mamers (Sarthe), which likewise owe their origin to 

 the action of incrustating water, approaches in character to that 

 of La Celle. The deposits in question have not yet been 

 exhaustively examined, but M. Crie" mentions among the plants 

 yielded by them the hornbeam (Carpinus bekclus, L.), the elm 

 (Ulmus campestris, L.), the oak (Quercus robur, L.), the gray 

 willow {Salix cinerea, L.), the hazel (Corylus avellana, L.), and 

 the hart's-tongue (Scolopcndrium officinale, Sm.) Besides these 

 there occurs the impression of a leaf, which appears to be that of 

 the fig-tree. The general facies of the flora, the same observer 

 remarks, implies a milder and more equable climate than now 

 characterises the west of France. 1 



1 Les Anciens Glimats et les Flores Fossiles de V Quest de la France, p. 61. 



