GREfiES. 41 



provided with wide lateral lobes which are united with one another at 

 the base. The tail is inconspicuous, being a mere tuft of downy plumes. 

 As in the Divers, the plumage of the Grebes is much handsomer during 

 the breeding-season than it is in winter, and they are familiarly known 

 on account of the muffs and trimmings for dresses which are made 

 from their beautiful silvery-white breasts. 



The Grebes are a nearly cosmopolitan family, though chiefly found in 

 the temperate regions of both Hemispheres. About twenty-five species 

 are known, all expert divers, but unlike some of the Auks and the 

 Penguins, which use their wings in diving, Grebes propel themselves 

 through the water by their curiously lobed toes alone. 



In winter they migrate from the colder parts and are then often to be 

 found at the sea, but they breed exclusively on fresh water, attaching 

 their floating nest of weeds to any convenient patch of reeds. The eggs, 

 which are from three to six in number, are bluish-white when first laid 

 but soon become stained with brown. Five species occur in the British 

 Isles, the Great Crested Grebe (Podicipes cristatus) (287) and the Dab- 

 chick {P . fluviatilis) (279) being residents, while the Ked-necked (286), 

 Eared or Slavonian (284), and Black-necked Grebes (285) are autumn- 

 and winter-visitors. The latter also occasionally appears in spring and 

 summer, and is believed to have bred in Great Britain. The most re- 

 markable is the large South American species (P. micropterum) , which 

 is found on Lake Titicaca in Peru, 13,645 ft. altitude, and lacks the 

 power of flight. 



Order VII. COLYMBIFORMES. 



Family Colymbid^. Divers. 



The Divers, or Loons as they are also called, present precisely similar [Case 21.] 

 modifications of the skeleton to those found in the Grebes. Indeed, the 

 two orders are very generally regarded as one. Like the Grebes, they 

 have a distinct breeding-plumage which dift'ers conspicuously from that 

 worn during the remainder of the year. The front toes are fully 

 webbed, and the tail-feathers, though small, are normal. The large 

 olive- or reddish-brown eggs spotted with black and grey are always two 

 in number, and laid in a slight depression of the ground close to the 

 water's edge. Though essentially formed for swimming and diving, 

 when once on the wing they can also fly with great rapidity, but on land 

 their movements are awkwaVd and clumsy. 



Of the five species known to inhabit the Arctic and sub-Arctic 

 portions of the Northern Hemisphere, four visit Great Britain, two, 

 the Red- throated (290) and Black-throated Divers (291), nesting within 

 our limits, and two, the Great Northern (293) and the White-billed 

 Divers (292), visiting our shores in winter, the latter very rarely. 

 In autumn they change their summer-plumage for a more sober garb, 



