January, 1921] 



The Canadian Field-Naturalist. 



9 



que ted states *'riie vanguard of the main 

 volume of the Liard driftwood reached Old 

 Fort Good Hope on the Lower Mackenzie 

 about July 13th ' '. This vanguard reached 

 our camp on the Liard at Gros Cap Island 

 about midnight of July 6th. The drift- 

 wood tlierefore required at most about 

 seven days to travel the distance between 

 these two i)oints, which is approximately 

 620 miles. This means that it was trans- 

 ported at an average rate of at least three 

 and three-quarters miles an hour, and 

 gives a good idea of the swift current of 

 the Mackenzie. 



The flood was caused by unusually warm 

 and abundant rains throughout the basin 



of the Liard. This river rises in and 

 drains a large area west of the main range 



of the Rockies between latitudes 58 deg. and 

 61 deg. 30 min. N. and then cuts through 

 this range to the eastward. The warm 

 rains not only caused the rivers to rise by 

 their own precipitation, but also rapidly 

 melted the mountain snows. That the 

 flood extended to its headwaters was shown 

 by the large number of huge trees in the 



. driftwood common in Northern British 

 Columbia, but entirely unknown in the 

 lower reaches of the river. We had only 

 six dry days out of six weeks on our trip, 

 wliicli accounts for the continued high 

 Avater all summer. 



VANCOUVER NATURAL HISTORY SOCIETY. 

 Naturalists Study Alpine Flora. 



The nintli of a series of excursions held 

 this summer by the Vancouver Natural 

 History Society took place last week end 

 when a party of 22 ladies and gentlemen 

 left on Saturday to study the flora of 

 Grouse, Dam and Goat Mountains. 

 Amongst those present Avere several mem- 

 bers of the University Summer School Bot- 

 any Class which finished work the previous 

 day, and this outing proved a fitting 

 climax to a strenuous term of indoor lect- 

 ures. 



TTnder the leadership of the President, 

 John Davidson, F.L.S., the party proceed- 

 ed via Lonsdale, Mosquito Creek, where at- 

 tention was directed to the devastating ef- 

 fect of erosion, which the President several 

 years ago foretold would result if logging 

 operations were carried on in that vicinity. 

 It was pointed out that the people of N. 

 Vancouver in future years will have to pay 

 for the folly of the present generation in 

 allowing erosion to commence through per- 

 mitting a logging company to obtain a few 

 thousand dollars Avorth of timber. Al- 

 ready trees, houses and bridges had been 

 destroyed at this point and greater havoc 

 is likely to take place Avithin the next fcAV 

 years. Continuing, the party travelled via 

 tlie B. C. Mountaineering Club's trail to 

 the Club's Cabin, use of AA'hich had been 

 kindly granted for the occasion. During 

 this part of the journey attention was 

 draAA'n to the changes in A^egetation corres- 

 ponding with the cliange in altitude. The 

 trees and undergroAvtli at first were sim- 



ilar to those found around Vancouver, the 

 Giant Cedar, Sitka Spruce, Hemlock, and 

 Douglas Fir, Avith undergroAvtli of Salal, 

 Huckleberries (Avhich are more abundant 

 than usual this year), and False Azalea, 

 while here and there Avere found patches 

 of PipsisseAva, a native plant used for medi- 

 cinal purposes. Higher up, near the 2,000 ft, 

 altitude. Western White Pine Avith its long 

 cones and leaves in clusters of five became 

 frequent, and occasional trees of YelloAv 

 Cedar and Western Ycav Avere observed, 

 the latter Avith its beautiful red berry-like 

 fruits in evidence. 



Dinner past, the evening Avas spent in- 

 specting a collection of pressed plants pre- 

 pared by one of the members who had re- 

 cently returned from a trip through the 

 drybelt. By this time, in spite of the light 

 smoke screen Avhich hung over the inlet, 

 the lights of VancouA'er AA^ere in evidence 

 and the party spent half an hour picking 

 out the various sections and streets of the 

 city; motor cars and inter-urban trains 

 Avere discernible by their strong head 

 lights. 



By half past six the folloAving morning 

 the cabin Avas astir, some getting break- 

 fast ready, others packing supplies for 

 lunch, Avhile novices looked on AAdth interest 

 at hoAv things Avere done by mountaineers. 

 Breakfast past the party Avas divided into 

 tw^o sections, one, under the leadership of 

 the Society's treasurer, Mr. Jas. Lyall, 

 taking the direct trail from the cabin to 

 the Plateau of Grouse ; the other, under the 



