7 
116 THE ESSEX NATURALIST. 
The throwing-up of “ pellets ’’ is advantageous to those birds. _ 
which practise the habit, since they are by this means spared 
certain internal complications from which other less-fortunate 
animals suffer. 
Thus, the Persian Goat not uncommonly forms concretionary 
masses in its intestine from the non-digestible food, which . 
are known as “ bezoar-stones ’’ ; and similar concretions have 
been met with, as abnormal products, in the intestines of 
various deer, antelopes and monkeys, and are regarded in 
the East as possessing medicinal qualities ; while in the crayfish 
a pair of limy concretions are normally formed in the gizzard, 
and are credited by German peasants with magical properties. 
The perfume ‘“‘ ambergris”’ is a fecal concretion formed in 
the intestine of the sperm whale, and contains fragments of 
the hard parts of the cuttle-fishes upon which the whale feeds. 
Various herbivorous animals, too, form what are known as 
“ hair-balls ’’ in their intestines. 
These are more or less pathological manifestations, men- 
tioned here only to show the need which many and diverse 
creatures experience to get rid of the non-assimilable residue 
of their food, a need which birds have so admirably met by the 
habit of regurgitation. Somebody has well said that vomiting: 
comes easy to birds, the wide gape, the short distensible zso- 
phagus and the strongly muscular crop which they possess, 
rendering the process an easy one. 
But not birds alone, though chiefly they, possess the pellet- 
casting method of ridding themselves of the indigestible residue 
of their food; other classes of animals, at least occasionally, 
exhibit the same habit. Certain reptiles and amphibians, 
for instance, eject “ pellets.” It is recorded of Natterjack 
Toads that “‘ when captured and placed in a box they vomit. 
pellets of wing cases and the indigestible parts of the harder 
beetles.’’* The Rattlesnake is similarly credited. An. observer 
records, ‘‘ Another strange observation was that sometimes these 
snakes disgorge pellets composed of hairs and feathers, after 
the manner of owls,’’5 anda Leopard Snake (Coluber leopardinus) , 
kept in captivity for a year, exhibited the same method of getting 
rid of indigestible food. “‘ Its last meal, which consisted of two 
mice, it disgorged about five days afterwards.’’® 
4 Zoologist, 1914, p. 388. 
5 Bulletin de la Société Zool. de France, 1897, p. 187. Zoologist, 1898, p. 93. 
6 Zoologist, 1901, Pp. 159. 
