91 8 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. Ptilopus, 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 Carclia and the 

 Ptjlarus. Occasionally it assumes peculiar shapes : in Carpophaga 

 latrans, another of the Pigeons, and in some Tubinares, 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 knoMTi 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 

 nodua, Cuculus canorus, and especially in Buceros. 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 SlrutMo, Rhea, the Anseres, 

 Phoenicopterus, Tantalus, Grus, the Columbse, Gallinse 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 rubicola 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, K6union, 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 Euficilla (REDSTART, p. 775), and only somewhat 

 more distantly to Saxicola (Wheatear), though for some occult 

 reason Dr. Sharpe (Cat. B. Br. Miis. iv. p. 113) referred it to the 

 Muscicapidse (Fly-catcher, p. 273). 



