424 
difficult to cross; a single worker stationed itself there and undertook to help the 
others over. It did this by taking part of the weight of the grain of corn and back- 
ing across ahead of its companion until it had got it in a safe place. After helping 
one it returned to meet another, and continued this apparently voluntary task as 
long as this systematic robbery lasted. 
CICADA CHIMNEYS — CONTRADICTORY TESTIMONY. 
In a note upon page 276 of the current volume of Insect Life we 
reviewed Mr. Benjamin Lander's theory as to the reason for " chimney- 
building" by the pupa of the periodical Cicada. Kecent correspond- 
ence with Mr. Lander, and with Mr. J. G. Barlow, of Cadet, Mo., has 
elicited some further observations made by these gentlemen, which are 
so diverse in character as to leave the question as far from solution as 
ever. 
The earlier supposition that these chimneys are built only upon low 
ground has been shown by Lintner to be unjustified, and seems to be 
further controverted by the observations of Mr. Lander, who has found 
them in great numbers on top of the Palisades of the Hudson, and by 
those of Mr. Barlow, who writes that he has found them mostly on a 
high ridge. Mr. Barlow also agrees with Mr. Lander in stating that 
the chimneys occur in numbers. where the undergrowth of saplings, etc., 
is thick, thus contradicting another suggestion referred to in onr former 
note, that the chimneys are built to afford the Cicada pupa an eminence 
upon which to crawl while shedding its skin and unfolding its wings. 
Mr. Lander's observations tend to show that the chimneys are built 
only where the soil is thin, covering a layer of rock or it may be a 
stratum of sand too light to burrow in. Mr. Barlow, on the other hand, 
reports finding the chimneys plentifully where the soil " was of reason- 
able depth, with a foot or more of clay, then gravel below." 
Mr. Lander's theory of the chimneys is, in brief, as we understand it, 
that owing to unusual warmth, either of the weather, as was the case in 
March, 1894, or perhaps of forest fires, such Cicada pupae as are near the 
surface of the ground are aroused to activity early in the season. "It 
does not seem unlikely," he then says, "that the wonderful intelligence 
of these marvelous creatures * * * would impel them to build 
closed extensions to their short burrows as a protection from the pre- 
mature heat * * * and possibly to shut out injurious intruders 
during the incidentally lengthened period they would nave to wait for 
full development over that of those who would later open their deeper 
shafts, unroofed, at the surface of the ground." But both the objects 
thus attributed by Mr. Lander to the Cicadas in building their chim- 
neys are apparently contradicted by the observations of Mr. Barlow, 
who says, "I have seen the most of them where there was a layer of 
dead leaves completely covering the chimneys from sight." 
These observations are so contradictory that it seems to us no definite 
theory can yet be formulated as to the purpose served by the chimneys. 
