928 SWALLOW 
India. or Burma, even further to the southward, occasionally 
‘reaching Australia, while those of North America, H. erythrogastra, 
extend their winter-wanderings to Southern Brazil; but, whither- 
soever they then resort, they during that season moult their 
feathers, and this fact affords one of the strongest arguments 
against the popular belief (which, curious to say, is still partly if 
not fully entertained by many who should know better) of their 
becoming torpid in winter, for a state of torpidity would suspend 
all animal functions.1 The chestnut forehead and throat, the shining 
steel-blue upper plumage and the dusky-white—in some cases 
reddening so as almost to vie with the frontal and gular patches— 
of the lower parts are well known to every person of observation, as 
is the markedly-forked tail, which is become provérbial of this bird. 
Taking the word Swallow in a more extended sense, it is used 
for all the members of the Family Hirundinidx,? excepting a few 
to which the name MARTIN (p. 536) has been applied, and this 
Family includes more than 100 species, which have been placed in 
many different genera. The true Swallow has very many 
affines, some of which range almost as widely as itself, while others 
(as the form resident in Egypt, Hl. savignit) seem to have curiously 
restricted limits, and much the same may be said of some of its 
more distant relatives. But altogether the Family forms one of the 
most circumscribed and therefore one of the most natural groups of 
OSCINES, having no near allies; for, though in outward appearance 
and in some habits the Swallows bear a considerable resemblance 
to SwIirFTs, the latter belong to a very different Order, and are 
not Passerine birds at all, as their structure, both internal and 
external, proves. It has been sometimes stated that the Hirun- 
dinide have their nearest relations in the Muscicapidx (FLYCATCHER, 
1 See John Hunter’s Hssays and Observations in Natural History, edited by 
Sir R. Owen in 1861 (ii. p. 280). An excellent bibliography of the Swallow- 
torpidity controversy, up to 1878, was given by Prof. Coues (Birds of the 
Colorado Valley, pp. 878-390), who seemed still to hanker after the ancient 
faith in ‘‘ hibernation,” as do apparently some other writers not so well informed. 
2 An enormous amount of labour was bestowed upon the Hirundinidz by 
Dr. Sharpe (Cat. B. Br. Mus. x. pp. 85-210), only commensurate, perhaps, 
with that required for an understanding of the results at which he arrived. It 
was to be hoped that in the finely-illustrated Monograph of the Family which he 
and Mr. Wyatt have published (2 vols. 4to, London: 1885-94), more of the 
many puzzles which the group offers would have been cleared up, but it still 
remains an intricate maze to tempt the adventurous. Mr. Wyatt's figures are 
very beautiful, but he is apparently one of those who believe that birds when 
flying at full speed do not extend their legs behind them. A curious omission 
of the authors is any reference in the work, with its copious bibliography, to 
the admirable account of the British Hirundinidex contributed by Gilbert White 
to the Royal Society (Phil. Trans. lxiv. pp. 196-201; lxv. pp. 258-276) and 
afterwards reprinted in the Natural History of Selborne (1789). 
