DIVER TIC UL UM 1 5 ; 



validity of which is not yet fully recognized. The Divers live 

 chiefly on iish, and are of eminently marine habit, though invari- 

 ably resorting for the purpose of breeding to freshwater-lakes, 

 where they lay their two dark-brown eggs on the very brink ; but 

 they are not unfrequently found far from the sea, being either 

 driven inland by stress of weather, or exhausted in their migra- 

 tions. Like most birds of their build, they chiefly trust to s\nm- 

 ming, Avhether submerged or on the surface, as a means of progress, 

 but once on the wing their flight is strong and they can mount to 

 a great height, whence on occasion they will rush downward with 

 a velocity that must be seen to be appreciated, and this sudden 

 descent is accompanied by a noise for which those who have wit- 

 nessed it will agree in thinking that thundering is too weak an 

 epithet. In winter their range is too extensive and varied to be 

 here defined, though it is believed never to pass, and in few direc- 

 tions to approach, the northern tropic ; but the geographical dis- 

 tribution of the several forms in summer requires mention. While 

 C septentrionalis inhabits the north temperate zone of both hemi- 

 spheres, C. ardicus breeds in suitable places from the Hebrides to 

 Scandinavia, and across the Russian empire, it would seem, to 

 Japan, reappearing in the north-west of North America,^ though 

 its eastern limit on that continent cannot yet be laid down ; but it 

 is not found in Greenland, Iceland, Shetland, or Orkney. C. 

 glacialis, on the contrary, breeds throughout the north-eastern part 

 of Canada, in Greenland, and in Iceland. It has been said to do 

 so in Scotland as well as in Norway, but the assertion seems to 

 await positive proof, and it may be doubted whether, with the 

 exception of Iceland, it is indigenous to the Old World, ^ since the 

 form observed in Nerth-eastern Asia is evidently that which has 

 been called C. adamsi, and is also found in North-western America ; 

 but it may be remarked that three examples of this form have 

 been taken in England, and two in Norway (Proc. Zool. Soc. 

 1859, p. 206, Nyt Mag. for Naturvidenskaherne, 1877, p. 218, and 

 Stevenson's Birds of Norfolk, iii. pp. 268, 269). 



DIVERTICULUM {d. cajcum \dtelli). After the yolk-sac has 

 been withdrawn into the body-cavity its stalk remains in connection 

 with the small intestine, and forms an appendix to it like a little 

 csecum, which often persists throughout life in the NmiFUGiE, and 



^ Mr. Lawrence's C pacificus seems hardly to deserve specific recognition. 



^ In this connexion should be mentioned the remarkable occurrence in 

 Europe of two birds of this species which had been previously wounded by a 

 weapon presumably of transatlantic origin. One had "an arrow headed with 

 copper sticking through its neck," and was shot on the Irish coast, as recorded 

 by Thompson {Nat. Hist. Ireland, iii. p. 201) ; the other, says Herr H. C. 

 Miiller {Vid. Medd. nat. Forening, 1862, p. 35), was found dead in Kalbaksfjord 

 in the Faeroes, with an iron-tipped bone dart fast under its wing. 



