ALBA TROS 



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 gi-ains 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 Ratitse, with 

 their Avell- developed air-sacs. The newer researches of Sappey,^ 

 Cam]3ana,2 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, Alcati'aze, 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 Diomedeidse,^ 

 a family of the group Tubinares, and especially to the largest species 

 of the genus, Diomedea exulans, the " Man-of-war bird " or Wandering 



^ Compt. Rend, da I' Acad, des Sciences, xxii. pp. 250, 508. 



- Physiologic de la respiration cJiez les Oiseaux. Paris : 1875. 



^ Jenaischc Zeitschrift, xix. pp. 174-327, 330-429. 



■* The word is Arabic, al-eddous, adopted from the Greek Kt£5os, water-pot 

 or bucket [cf. Dozy & Engehnann, Glossaire des mots espagn. et 2}ortug. derives de 

 I'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 j'onng in the 

 wilderness. 



^ The Arcs Diomedeai 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 disscrtatio. Amstelodami ; 1672, p. 23), seem to have been Shear- 

 WATEKS of some sort. 



