324 BULLETIN OF THE BUSSEY INSTITUTION. 
No. 29. — Cherry-stones eaten by the Domestic Pigeon. 
3y F. H. Srorer, Professor of Agricultural Chemistry. 
In August, 1881, I noticed that a pair of pigeons belonging to 
the neighborhood began to visit the roof of the large stone building 
of the Bussey Institution very frequently, and supposing that they 
intended to build a nest there I kept an eye on their movements 
with the intention of preventing them from so doing, for the build- 
ing had previously happily been free from the visits of such birds. 
It soon appeared, however, that the pigeons had no intention of 
nesting on the building, and that they had simply fallen into a 
habit of resting quietly several hours each day in one particular 
corner of the roof which was sheltered from the sun’s rays, and in 
this habit they persisted during August and September and the 
earlier part of October, and indeed in some measure for a much 
longer period, as will appear in the sequel. 
Early in October I noticed that a considerable quantity of dung 
had collected on the roof beneath the roosting-place of the birds, 
and in giving directions for its removal I was surprised to see that 
it consisted almost wholly of broken cherry-stones. At first sight, 
indeed, the dung seemed to be mere gravel and it was so 
described by the laborer employed to remove it, but on closer in- 
spection it appeared that the supposed gravel really consisted of 
fragments of cherry-stones of all conceivable shapes and sizes 
from the magnitude of one third a mazzard stone down to the 
merest dust. At the time of this first collection there was some- 
thing like two quarts of the broken stones which had been passed 
by the two pigeons in the course of little more than two months, 
and that during the intervals of time which they had spent at this 
eorner of the roof which was not their proper home and had served 
them only as an occasional resting-place. In all this mass of 
fragments I could detect only two whole unbroken cherry-stones, 
one large enough to have been a mazzard and the other as small 
as a choke-cherry stone. ‘There was one fragment which was 
plainly half a mazzard stone, but most of the pieces were no larger 
than one quarter or one third of a stone, as has been said. Four 
or five quartz pebbles were found also among the dung, each of 
them as large as a mazzard-cherry stone. 
From the lateness of the season at which some of the dung had 
