HABITS OF BIRDS 
the woodpecker, but in this case it is made to assist in the 
capture of its food ; many other instances can, no doubt, be 
brought forward, showing the power that birds have of ridding 
their stomachs of that part of their food not required for their 
nourishment. One very remarkable instance I well remember. 
A year or two ago I found in my garden, in a small heap, about 
a handful of the most beautiful blue pills, the size of peas, 
and studded all over with brilliant and shining blue fragments ; 
I soon discovered that they were the castings of tlie flycatchers 
that had a nest immediately above the spot upon which I found 
them ; the charming colour was due to the outer skins of the 
bluebottle flies upon which the birds had fed. All the insect- 
feeding birds throw up pellets consisting of the refuse or in- 
digestible parts of the insects they swallow, just in the same 
way as the Eaptorial birds (as hawks, owls, etc.) cast up the 
feathers, bones, hair, and food of grain-eating animals in the 
form known as castings or pellets. 
“In conclusion, I think it may be fairly reasoned that it is 
much more likely that the food-pellets of the male hornbill are 
intended for the support of the female and young, and belong 
to the natural and healthy condition of the birds which produce 
them, than that they are the result of indigestion or disease. 
For v/e see that the power and habit of casting up from the 
stomach are of frequent and common occurrence among birds, 
and we also find that the secretions of the oesophagus are 
used as food for the young of many species of birds ; in the 
parrots and pigeons I think this is universal. 
“Another strong argument in favour of my belief is to be 
found in Dr. Livingstone’s statement that ‘ the male bird, by 
his constant attention upon the female, becomes so prostrate 
and exhausted that a slight change in the temperature causes 
him to fall down and die.’ 
“It cannot be supposed that the mere collecting food for the 
female is the cause of this fatality, it is doubtless the over- 
taxing of the system by the constant secretion of this nutritive 
matter, reminding one of the blood in the nests of the esculent 
swifts after the birds have been robbed of the first and second 
nests. But the most positive proof of finding this package of 
food is given, without, however, understanding its use, in the 
extract from the Eew T. Phillips’ MS. before referred to.” 
Having once established the fact, all that is required is 
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