238 THE BIRDS OF THE BRITISH ISLES. 



a lip, is the entrance to the real nest within, a cup of grass or 

 sedge, nearly as large as the nest of a Blackbird, lined with 

 leaves of oak, beech or other trees. Four to six white eggs 

 (Plate 84) are laid in March or April, and two or three broods 

 are reared, often in the same nest. I have found fully fledged 

 young at the end of March. When disturbed the young, when 

 hardly feathered, will at once drop into the water and dive ; I 

 have seen them swim under water, washed down stream, and 

 crawl out yards below, at once seeking shelter under stones. 



The head of the adult Dipper is umber brown, the back slate- 

 o-rey mottled with black, looking quite black from a distance, 

 and the wings and tail are brown. The throat and upper 

 breast are white, followed by a band of warm chestnut which 

 merges into black on the belly and flanks. The bill is almost 

 black, the legs and irides brown. The young are greyish 

 brown and have no chestnut band. Length, 7 ins. Wing, 375 

 ins. Tarsus, I'l ins. 



Family TROGLODYTID^. Wrens. 



Wren. Troglodytes troglodytes (Linn.). 



The Wren, found throughout Europe, is only migratory in the 

 northern part of its range. Its sober barred dress is subject to 

 considerable variation, and where, in ages gone by, colonies 

 have been isolated, the variation has become constant in one 

 form or another. Thus in the British Isles, in addition to the 

 typical bird (Plate 89), there are two distinct insular forms ; 

 one, T. t. hirtetisis Seebohm, is confined to the island of St. 

 Kilda, and another, T. t. zetlandiacs Hart., to most, at any rate, 

 of the Shetlands. In these two forms colour variation is of less 

 importance than the greater size and strength of the beak and 

 feet. Numbers of northern Continental Wrens reach us in 

 autumn ; some may be winter visitors, but many certainly are 

 birds of passage. 



