10 
cliincli-bugs began to escape almost at once; but by steepening the 
furrow at this point with a hoe, we confined them permanently, 
only a very few escaping by making here and there a temporary 
passageway which permitted now and then one, at long inter\ als, 
to emerge. Such passageways were presently undermined, and 
the number escaping was entirely insignificant. 
Chinch-bugs began to collect in the can as soon as they were 
placed in the furrow, but the angle of the furrow near it arrest¬ 
ing them, a second one was placed in the middle of the furrow. 
Into this can they fell in quantity, presently marching towards it 
from the right and left, thinning out the crowd in the furrow for 
a distance of nine feet on one side and ten to twelve feet on the 
other, until by 9 o’clock the attack was practically broken all 
along the line by the capture of nearly all the bugs. ' % 
At 6:45 the temperature of the ground, the thermometer being 
lightly covered with dust, was 79 ; that of the air, in the sun, 82 . 
At 8:15 the temperature of the dirt, taken as above, was 97% 
and that of the air, 85°, the thermometer erect in the sun. 
At 9, chincli-bugs had begun to die where most exposed to the 
sun. Dirt was here 108°; air, 87A°, with thermometer erect. 
No. 4. July 12, a patch of wheat stubble was cleared off, as 
in experiment 1, and at 7:30 p. m. a belt of coal-tar two inches 
wide was put dowm, forming an oval enclosing a space twenty- 
five feet long by two feet across. Post-holes about ten inches 
deep were dug at either end with a common post-hole digger. 
Coffee cans, about six inches in diameter and seven or eight 
inches in depth, were placed in the post-holes so that the 
entrapped chinch-bugs could be easily removed and measured. 
At 7:45 p. m. half a pint of chinch-bugs was distributed over 
the hard smooth surface within the enclosure. At first they went 
in all directions, and many ran headlong into the tar and were 
destroyed; but the greater number were more deliberate, and 
moved up and down the tar line without making any attempt to 
cross it. By 7:50 a large proportion had passed from the middle 
of the enclosure to the edge of the coal-tar, principally on the south 
side, but forming a belt around the entire enclosure, the general 
movement being eastward. 
At 8 o’clock they were less active and were most abundant at 
the ends of the oval, but very few had fallen into the post-holes. 
There w r as no disposition to climb rootlets or other projections 
above the surface. 
At 8:30 they were still less active, and were collecting together 
in masses on small lumps of earth and in depressions on the 
surface. No general movement observed at this time. About 
fifteen hundred chinch-bugs were removed from each can. They 
■were most abundant in the east and w’est ends and along the south 
side of the oval. The slightest disturbance, such as the move¬ 
ment of a finger on the ground in their midst, caused the greatest 
confusion among them. 
The sky w r as clear, with a gentle breeze from the west, dem- 
perature of air at 7:30 was 82 , the thermometer held eiect, sui- 
