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BULLETIN OF THE BUSSEY INSTITUTION. 331 
remarked upon both by myself and by members of my household 
at a time when we had no inkling that the birds had been consum- 
ing a particularly indigestible food. It is not impossible, on ‘the 
other hand, that the satisfaction derived from the cherry-stones 
may be due to the chemical composition of their kernels rather 
than to any mechanical action. It is true at all events that the 
meat within cherry-stones, both that of the wild and of the culti- 
vated species, has a very strong flavor of bitter-almonds, which 
indicates the presence of prussic acid, and it is within the bounds 
of possibility that this component of the kernel may act as a seda- 
tive or composing medicament and so comfort the birds. However 
this may be, it is none the less extraordinary that birds accustomed 
to flying and whose safety must often depend upon the power of 
instant and speedy flight should willingly load themselves down 
with such quantities of heavy ballast. It is known from European 
experience that the domestic pigeon, besides eating many very hard 
seeds of weeds, is extremely fond of beech-nuts. So, too, the wild 
passenger-pigeons of America, and the Carolina turtle-dove also, 
eat beech-nuts and acorns. But while less unlike cherry-stones 
than most other items in the ordinary diet of the domestic bird, the 
shells of these nuts seem like mere paper when compared with the 
hard lignine of the cherry-stones. 
As bearing on the question of the value of pigeon-dung as a 
fertilizer it is worthy of remark that the observation above described 
goes:to show the possibility that at certain seasons of the year the 
sweepings of the dove-cote may be largely composed of matters 
that are inert and of themselves useless as manure; in which event 
it would be erroneous to repose too securely upon the traditional 
high estimation in which this form of manure has always been held. 
Nore 1. — Since the foregoing article was written I have ob- 
served that Snell,* in discoursing upon the influence of experience 
on the selection of food by animals, has alluded in a somewhat dif- 
ferent sense from that above stated to the notion that pigeons may 
mistake cherry-stones for peas. ‘‘ Young doves,” he says, ‘‘ pick 
up cherry-stones and throw them away again after they have con- 
vinced themselves, by (repeatedly) taking them in their beaks and 
again dropping them, that they are not peas.” Snell’s observation 
is of interest, however, as going to show that the birds only gradu- 
ally accustom themselves to this seemingly unnatural food. 
* « Jahrbiicher des Vereins der Naturkunde in Nassau,” 1861, Heft 16, p. 208. 
