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MOUNTAIN SWARMING OF VANESSA CALIFORNIA. 

 By C. L. Hopkins. 



During an ascent of Mount Shasta, made iu August, 1889, a most 

 interesting occurrence was noted in the flight of countless myriads of 

 butterflies (Vanessa califomica) at an altitude far above snow-line. 



In our early morning climb of August 29, of the above year, we bad 

 left our horses at half past 4 o'clock, at what is known as " Horse 

 Oamp," at very near snow-line, where there were many small snow fields 

 close about us. Our progress was very slow and tedious, being all of 

 the time over loose, sliding fragmentary rocks, or the almost smooth, 

 hard-frozen surface of the icy snow, and which latter did not soften till 

 long after the sun had swung high enough to shiue full upon it. Some 

 little time after day-light, but long before we could see the sun, as he 

 was hidden from us by the high crest of a sharp ridge on the southwest 

 aspect of the mountain (our ascent being made from Sissous, west of 

 the mountain), a few signs of insect life were seen in the shape of " snow- 

 fleas," two or three large-winged grasshoppers, and, occasionally at 

 tirst, a butterfly. The last two were stiffened by the cold as if they were 

 there from the day previous. The latter insect increased much in num- 

 bers as we ascended, and were many of them found in among and under 

 the loose stones as well as a few upon them. 



At perhaps half past 9 we came to a point upon which the sun had 

 long been shining, and here they were flying in the air, the flight being 

 in a southeasterly direction. From here they seemed to iucrease very 

 rapidly in numbers up the remainder of the ascent to well toward the 

 summit. The latter was reached at 11.20 a. m.; the temperature was 

 noted at 42° Fah. iu the open air. We remained here about a half hour, 

 then passed down by way of the Hot Sulphur Spriugs, and then out on 

 the southerly face of the mountain. We again encountered our beauti- 

 ful friends at not farther than six or eight hundred feet below the ex- 

 treme peak, and now in countless numbers, Ailing the air with their 

 flashing wings, ami all passing in the same direction as observed dur. 

 ing the ascent — towards the southeast. This strange sight continued 

 until we seemed to pass below them, at au altitude of between 11,000 

 and 12,000 feet. The fact of its being a continuous flight of these in- 

 sects across the mountain in one direction during the warm part of the 

 day — a period of nearly five hours — is beyond question. That it was in 

 progress one or more days previous to that upon which 1 observed it is 

 an easy deduction from the fact of the numbers of the insects found 

 among the rocks and stones while yet stiffened by the cold of the night 

 air. How much longer it may have continued I had no means of 

 knowing. 



