CONTINENTAL NOTES FRANCE. 65 



of an insular or coast climate, and of the mountains." As to 

 its degree of resistance to cold, M. Jolyet quotes a M. Charles 

 Baltet to the effect that in Central and Eastern France the plant 

 froze at- i8° F., though in the Bois de Boulogne it was merely 

 "fatigued" at- 15° F. Unfortunately it is not clear what age 

 these plants were. What tries a tree is long-continued cold 

 with days of bright sunshine. The habitat of the Douglas 

 extends northwards to the Jan. isotherm of 14° F. (which 

 passes through St Petersburg), and southwards to the July 

 isotherm of 84° F. (which cuts Algiers). It is the Colorado 

 Douglas which reaches this southern point. Whereas on the 

 Pacific coast the annual rainfall is 31-5 inches, and may 

 rise to nearly 80 inches, the Colorado Douglas is found in 

 regions where the mean rainfall is small — perhaps 20 inches. 

 As to tenderness to spring frosts the Douglas and spruce are 

 about on a level. M. Parde states that natural seedlings of 

 Douglas are to be seen at Les Barres (in the Department of the 

 Eure) and in many other places — a most encouraging sign. 



Finally M. Cannon, who has interested himself in the Pacific 

 Douglas for thirty-five years and grown it for twenty-six, gives 

 us his experiences. He has not found the tree to be exacting 

 from the point of view of humidity. His land is meagre and 

 arid, and the summers are very dry and hot. The mean 

 rainfall is 23 inches and it is irregular, so that the droughts 

 are long, while the evaporation from the light sand of the 

 place is enormous. M. Cannon has a 40-year-old Pacific 

 Douglas, placed, isolated, in a very dry and sterile corner, 

 where even grass will not grow. This tree stood through 

 tremendous droughts in 1876, 1893, i900> s-i^d 1906, which 

 were enough to kill off a great part of his Scots pine planta- 

 tions. In 1879-1880, while still young, this tree withstood a 

 frost of probably some 50°. It is now 52 feet high and 

 6^ feet girth at 4^ feet from the ground, and is in perfect 

 vigour. M. Cannon has cultivated this species in a nursery 

 since 1883, and, after the first year, always in the open j and it 

 is no doubt the case that the winters of his country are vastly 

 colder than with us. Occasionally an unseasonable frost will 

 nip a shoot, but it is quickly re-formed, and, we may note, 

 the capacity to re-form its leader easily is a great point with 

 the Douglas. At the same time, none of these gentlemen 

 seem to notice the risk from exposure that Douglas suffers, 



VOL. XXIII. PART I. E 



