6 ALBATROS 
mental purposes, by inflating the skin, rustling the feathers, or 
acting as resounding bags in the Prairie-fowls and in the Emeu. 
The suggestion that the warm air in these sacs makes the bird 
lighter, and assists, balloon-like, the flight, is void of practical 
value, because the few grains of weight lifted up by the whole 
amount of air-sacs of even a large bird would be more than counter- 
balanced by a few grains of food or better-nourished condition of 
the bird. Nor would this view be applicable to the Ratite, with 
their well-developed air-sacs. The newer researches of. Sappey,! 
Campana,? and Strasser ® make it probable that one of the principal 
functions of the air-sacs consists in the ventilation of the lungs, the 
latter being only capable of very limited expansion and contraction 
in birds. No exchange of gas seems to take place in the sacs them- 
selves, they being poor in blood-vessels; but they seem to be 
directly connected with the regulation of the exhalation of aqueous 
vapour, there being besides no perspiration through the skin. 
Frequently they serve also as reservoirs for air, in order to increase 
the voice ; for instance, in the long-continued song of the Nightingale, 
or still more so, in the Lark when warbling. 
ALBATROS, a corruption of the Spanish and Portuguese 
Alcatraz or Alcaduz* by which name the Pelican is known in some 
parts of the Iberian peninsula and the Spanish colonies in the West 
Indies ; but it is also applied vaguely to other large sea-birds. By 
English navigators its use was formerly quite as indiscriminate, 
and its spelling no less so, the forms Alcatraza, Alcatraze, Algatross, 
and Albitross, occurring in various authors—the last being that 
found in Shelvocke’s Voyage (London: 1726), wherein (pp. 72, 73) 
is recorded the incident that, on Wordsworth’s suggestion, Coleridge 
immortalized in his Ancient Mariner. In process of time the name 
has become definitely limited to the larger species of Diomedeidz,® 
a family of the group T'ubinares, and especially to the largest species 
of the genus, Diomedea evulans, the “‘ Man-of-war bird” or Wandering 
1 Compt. Rend. del Acad. des Sciences, xxii. pp. 250, 508. 
? Physiologie de la respiration chez les Oiseaux, Paris: 1875. 
3 Jenaische Zeitschrift, xix. pp. 174-327, 330-429. 
4 The word is Arabic, al-cddous, adopted from the Greek xddos, water-pot 
or bucket (cf Dozy & Engelmann, Glossaire des mots espagn. et portug. dérivés de 
l’ Arabe, ed. 2, p. 79), and especially signifying the leathern bucket of an irrigating 
machine. Thence it was applied to the Pelican, from the resemblance of that 
bird’s pouch, in which it was believed to carry water to its young in the 
wilderness. 
5 The Aves Dionvedew of Pliny (lib. x. cap. 44), whence the word has been 
preserved in Ornithology, inhabiting the islands of the same name, generally 
identified with Tremiti off the Adriatic coast of Italy (cf Lachmund, De Ave 
Diomedea dissertatio. Amstelodami: 1672, p. 28), seem to have been SHEAR- 
WATERS of some sort. 
