BIOLOGICAL RECONNOISSANCE AT FLATHEAD LAKE. 103 



initiated, never having climbed before to such a height or been in such a 

 trying place. The result was interesting both to himself and the others. 

 The sight was too much, and his nerves refused to stay under control. All 

 his will power was not sufficient to hold his muscles in control, and ha 

 shook as with a palsy. Places that could be passed with a step were try- 

 ing and difficult, and often required minutes to get over. He reported it 

 seemed as though all the rocks were loose and ready to tumble down, 

 and to see him pick and try at rocks to see if they were stable was under 

 most circumstances really amusing. Under present conditions it waa 

 trying. Needless to say the rocks were solid. It is sufiicient to say 

 that in such attempts either all reach the summit together, or all return 

 together without reaching it. The higher we ascended on the peak tha 

 sharper the ridge became, and the steeper, and with this there was 

 greater trepidation on the part of the shaking member of our party. 

 Constant encouragement was necessary, and repeated lifts and boosts 

 were given. Although a man of mature years and of careful habits, or^ 

 dinarily calm and deliberate, he reached a point where he had no confi- 

 dence in himself, and even refused to stand erect on places that were per- 

 fectly safe and with abundant room. All this was the result of tha 

 effect of the crags, cliffs, waterfalls, and peaks on such an immense scale 

 that it was too much for the nervous makeup to stand, and there was a 

 collapse. When the collapse came it was quite complete, and lasted until 

 the foot of the mountain and camp were reached. Needless to say the 

 result was to make the individual exceedingly weary. Long before tha 

 others were tired he was almost overcome, though this was most notice- 

 able after the last cliff and crag were out of sight behind. 



The last thousand feet of rocks were almost completely bare. But 

 at the altitude of about 8,500 feet, as indicated by the aneroid, we cama 

 across a small shell among the rocks, on the summit of the ridge. This 

 little shell belongs to the Pyramidula, and is known as P. strigosa var. 

 alpina, and was found in considerable abundance. While the others 

 went on the conchologist devoted a quarter of an hour to the search, re- 

 sulting in securing some two or three dozen and several live ones. No 

 doubt many could have been found if search had been made, as they were 

 picked up occasionally almost to the summit. There was very little vege- 

 tation on which these shells could live, an occasional plant with a few 

 leaves and a stunted stem being seen here and there on the rocks. Asida 

 from this there was nothing to decay. The trees had long since been left 

 behind and there was nothing else alive visible, save the lichens. 



These shells reveal a very interesting point in adaptation. A near 

 relative has been found on the high mountains in various portions of fha 

 State of Montana. Pyramidula strigosa Gld., small variety, has been 

 taken on the sides of nearly all the high mountains in the western part 

 of the state. They have been collected at an altitude of from 8,000 to 9,000 

 feet in the Tobacco Root mountains in the eastern part of the state^ 

 Pyramidula strigosa Gld., var. cooper! W. G. B., is found along the shores 

 of the lakes and along the damp banks of the streams. Apparently some 

 of the lower forms have ascended, becoming accustomed to altitudes abova 



