918 STONE-CHAT 
forms a thickened pad which by contraction of the spirally-arranged 
muscular fibres presses upon and slides over the opposite corre- 
sponding pad. Péiilopus, one of the PIGEONS, possesses four such 
pads, and the cavity of its Gizzard appears cross-shaped in a trans- 
verse section. The cuticle between the pads generally shews 
irregular folds which end suddenly towards the Cardia and the 
Pylorus. Occasionally it assumes peculiar shapes: in Carpophaga 
latrans, another of the Pigeons, and in some Tulinares, it forms 
conical processes which have been wrongly described as horny 
structures (p. 724); in Plotus the pyloric chamber is beset with 
hair-like filaments which permit nothing but fluid matter to pass 
into the duodenum. 
As a rule the cuticle, which exists also in the Simple Gizzard, 
though there not hardened, is continuously wearing away and being 
reproduced, but many cases are known in which most of the lining 
is suddenly cast off and ejected through the mouth, as has been 
observed in Pastor roseus, Sturnus vulgaris, Turdus viscivorus, Carine 
noctua, Cuculus canorus, and especially in Luceros. Another peculi- 
arity is that the Gizzard of Cuculus canorus and of Harpactes is fre- 
quently lined with the broken-off hairs of the Caterpillars swallowed, 
which, penetrating the cuticle, assume a regular spiral arrangement 
due to the rotatory motion of the muscles. The Compound 
Gizzard is most typically developed in Struthio, Rhea, the Anseres, 
Phenicopterus, Tantalus, Grus, the Columbe, Galline and in many 
Passeres, that is to say in Birds which mainly live on grass and 
seeds, and therefore need a mechanical apparatus to prepare the 
food for the action of the several digestive secretions, to aid which 
preparation stones are very frequently swallowed and retained in the 
organ. The compound muscular stomach, a substitute for the 
wholly lost TEETH, is a peculiarity of Birds. 
STONE-CHAT, the Motacilla, Saxicola or Praticola rulbicola of 
ornithology, one of the few “soft-billed” birds that are perenially 
resident as a species in this country. The black head, ruddy breast 
and white collar and wing-spot of the cock render him a conspicuous 
object on almost every furze-grown heath or common in the British 
Islands, as he sits on a projecting twig or flits from bush to bush, 
uttering a cheery song or the alarm-note whence he takes his name. 
This species has a wide range in Europe, and several others more or 
less resembling it inhabit South Africa, Madagascar, Réunion, and 
Asia—both the mainland and some of the islands from those of the 
Indian Archipelago to Japan. The genus Praticola is no doubt 
nearly allied to /uticilla (REDSTART, p. 775), and only somewhat 
more distantly to Sawicola (WHEATEAR), though for some occult 
reason Dr. Sharpe (Cat. B. Br. Mus. iv. p. 113) referred it to the 
Muscicapide (FLY-CATCHER, p. 273). 
