69 
Some notes on the character of the huts may be appended. The fact 
that there is no exit orifice at the ground, as described by Mr. Bath- 
von, is confirmed by the studies made by the observers cited above, 
the insect invariably clawing- its way out at the top. Mr. Lander notes 
one instance where the pupal shell remained attached and stuck in 
the summit of the burrow, the mature insect having escaped. Accord- 
ing to Mr. Lander, also, the huts are probably constructed at night, the 
insect taking advantage of the moist air, which would prevent the too 
rapid drying of the earth used in making the little tower and also of 
the delicate soft insect itself. As described by Dr. Lintner, the cham- 
bers are constructed with soft pellets of clay or mud brought up from 
below and pressed firmly into place. On examination, it will be seen 
that they are well rounded and rather firmly compacted within, although 
the marks of the claws of the pupa 4 are usually visible and leaves and 
sticks are often incorporated in the walls. No one has actually observed 
the insects while at work on these structures, and, although Mr. Lander 
repeatedly broke off a number of cones to see if they would be 
repaired, the insect failed to do so while being watched. Subsequently 
the broken portions were found to be recapped, but at some little dis- 
tance below the broken edge. In this connection may be quoted the 
observation of Mr. Lawton, of Nyack, cited by Dr. Lintner. Mr. Law- 
ton found that in every case except one the pupa repaired the cones 
soon after the injury by bringing up pellets of mud and roofing over 
the broken portion about half an inch from the top. The repairs were 
begun on one side and gradually extended over the opening horizon- 
tally, there being no attempt to form a dome shaped roof. In some 
instances the repairing of the chamber began within a quarter to half 
an hour after injury had been caused, and within three or four hours 
the opening was entirely closed over. On one occasion a pupa was 
caught with a pellet of mud in its claws. 
The fact that these cones had been noted only on two or three occa- 
sions prior to 1884 led to the belief that they were very rare and 
abnormal. Their extraordinary abundance in 1881 in connection with 
Brood XII would seem to indicate that they are by no means as rare as 
heretofore supposed, and it may be inferred that the absence of records 
is simply due to the lack of examination, especially in localities where 
the conditions would be favorable for their appearance. This view is 
confirmed by the announcement in a recent letter from Mr. Davis of 
the discovery of a cone April oO, 1898, on State u Island belonging to 
Brood XVII, which appears this year. He says that the cone was just 
appearing above the dead leaves, which, with the ground also, were 
"soaked after the wet days just past.* 1 This belief is participated in 
by Dr. Lintner in his last report on this interesting subject. 1 It should 
not be forgotten, however, that the great mass oi' the insects emerge 
without making any superficial construction whatever. 
Twelfth Report, [nsects, New York, p. 283. 
