706 OBSERVATIONS ON THE SUNDEW. 
I experimented with three species of these plants— D. filifor- 
mis, D. longifolia, and D. rotundifolia. I carefully removed them 
from all atmospheric agitation, and found they were the most 
active on the eleventh of July. I will therefore give the record 
of this day’s experiments, and the state of the weather. 
July 11th, thermometer stood thus—7 A. M., 68°; 2 p, Mi 193 
9 p. m., 69°. Rain early in the morning, one-third of an inch. 
Wind in the morning, N. E.; 2 P. m., S. E.; 9-p.m., S. E. ; with 
rising barometer from 29:96 to 30-05. 
July 11th, 10 o’clock, a.m., I pinned some living flies half an 
inch from the leaves, near the apex, of D. filiformis. In forty 
minutes the leaves had bent perceptibly toward the flies. At 
twelve o’clock the leaves had reached the flies and their legs were 
~ entangled among the bristles and held fast. I then removed the 
flies three-quarters of an inch farther from the leaves. The leaves 
still remained bent away from the direction of the light toward 
the flies, but did not reach them at this distance. 
Whether the action of the flies’ wings may have created suffi- 
cient foree to bring the leaves near enough to entangle the flies is 
a question I have not yet satisfactorily settled in my own mind, 
for dead flies did not seem to have the same power as living ones. 
Fifteen minutes past ten of the same day, I placed bits of raw 
beef on some of the most vigorous leaves of D. longifolia. Ten 
minutes past twelve, two of the leaves had folded around the beef, 
hiding it from sight. Half past eleven of the same day, I placed 
living flies on the leaves of D. longifolia. At twelve o’clock and 
forty-eight minutes, one of the leaves had folded entirely around 
its victim, and the other leaves had partially folded and the flies 
. had ceased to struggle. By half past two, four leaves had each 
. folded around a fly. The leaf folds from the apex to the petiole, 
after the manner of its vernation. I tried mineral substances, 
bits of dry chalk, magnesia and pebbles. In twenty-four hours 
neither the leaves, nor the bristles had made any move like clasp- 
ing these articles. I wet a piece of chalk in water, and in less 
‘than an hour the bristles were curving about it, but soon un- 
folded again, leaving the chalk free on the blade of the leaf. 
The bristles around the edge of the leaf of D. rotundifolia are 
longer than on those of D. longifolia, but the leaf of the former 
does not fold around a fly as it does in the latter — simply the 
bristles curve around the object, the glands on the ends of the 
