272 GENERAL ZOOLOGY 



which about twenty species are known, are confined to the 

 Antarctic regions. They live the greater part of the time 

 in the open ocean where their short wings (inadequate for 

 flight) are used for swimming. When on land, penguins, 

 walk erect or, if in haste, slide along on the belly. They 

 nest on land in great colonies during the Antartic summer 

 at temperatures as low as 78F. below zero. Several birds 

 often cooperate in incubating the eggs and caring for the 

 young. y^The cassowaries, emfcus, ostriches, and rheas' are 

 large-inning birds with small wings and large, powerful 

 legs. The. ostrichesDop camol birds (Struthio -eamvlus) , 

 live in the desert regions e^AMea, and travel about in 

 groups. These are the largest living birds, some indi- 

 viduals attaining a height of eight feet and weighing over 

 three hundred pounds. They are very shy and flee swiftly 

 when approached; but do not hide their heads in the sand, 

 as is commonly believed. Ostrich farming is now a well- 

 established industry in South Africa and certain parts of 

 the United States. A domesticated ostrich will yield 

 fifteen or twenty dollars worth of plumes each year. The 

 utilization of such feathers is desirable, for plucking causes 

 the ostrich little inconvenience and the use of the plumes 

 saves the lives of many wild birds which might otherwise 

 be slaughtered on the altar of fashion. The tinamous are 

 birds inhabiting Mexico, Central and South America. 

 They resemble partridges in appearance, but fly very little. 

 The flying birds are divided intovteHr orders. The loons 

 and grebes (Colymbiformes) are strong flyers but are chiefly 

 remarkable "for their ability to swim and dive. A loon can 

 stay under wat&\several minutes, and travel a quarter of 

 a mile while submerged./ The albatrosses, fulmars, shear- 

 waters, and petrels (P^ocellariformes) are gull-like marine 

 birds with tubular nostrils\and long slender wings. They 

 are expedient flyers and riesVin grWt colonies on Oceanic 

 islands. /The stork-like birds (Ciconiiformes) include the 

 tropic birds, Ciinnoran-ts, anhingas, pelicans/ herons/ bit- 

 terns, spoonbills, storks, ibises, flamingoes/etc. Most of 



