32 NATURAL HISTORY OF BIRDS. 



tance of the structural characters peculiar to this super-order clearly understood. A 

 few impotent attempts had been made to give the Struthious birds a position in the 

 system corresponding to their peculiarities, but most ornithologists contented them- 

 selves by conceding them rank as a "family," or, at the most, as an "order," while 

 others adhered to the arrangement of the eighteenth century, in regarding them only 

 as separate genera, with which they associated a few forms of somewhat similar hab- 

 its and superficial resemblance, for instance, the bustards, in a conglomerate group, 

 designated by the name of Cursores. To Huxley is due the honor of vindicating their 

 right to be regarded as primary groups, though he failed to include the Tinamous 

 ( Crypturi), his Dromreognathae par excellence, a name we have here adopted to signify 

 all the dromseosnaathous birds with true bird tail and without teeth. 



ORDER I. STRUTHIONES. 



Our knowledge of the large forms constituting the first order of living birds can 

 hardly be said to be more than twenty-five years old. True, all the typical species 

 were known long ago, but a more thorough examination and understanding of 

 the group is of rather recent date. Then, only five or six species were known ; now 

 we recognize about twenty forms; their affinities, their internal and external anatomy, 

 and partly their development, have been investigated during the last quarter of a 

 century, and more accurate information concerning habits and nature of these birds 

 has replaced the old yarns and fables imposed upon credulous travelers by ignorant 

 savages. Ornithology is here bound to thankfully acknowledge the aid derived from 

 the zoological gardens, and what has been accomplished may be taken as a fail- 

 promise of what we have to expect in the future. For if we are going to study the 

 birds, we must study the whole animal, and not the stuffed skin alone ; the feathers 

 constitute an important and peculiar part of the bird ; but the bird is also a vertebrate, 

 and should be treated as such. 



The members of this division are characterized by the great development of the 

 hind extremities for terrestrial locomotion, hence, the legs are high and stout, and the 



j Zj 



neck is correspondingly long and slender. The bill is broad at base, depressed, not 

 longer than the head, and the nostrils, though not placed at the extremity of the bill, 

 as in Apteryyes, are situated further from the base than in most other birds ; the 

 mouth is deeply split. None of the living forms have more than three toes, and some 

 of them the African ostrich and its nearest allies have only two, by suppression of 

 the third toe. It has been usually taught that the Struthiones have no lower larynx, 

 or 'syrinx,' as the rest of the birds, but Prof. Forbes's investigation shows that this 

 is totally erroneous, and since the mistake is still repeated in works of rather recent 

 date, it may be useful to repeat the conclusion he arrived at, as follows : "As regards 

 the alleged absence of a lower larynx (or 'syrinx') in these 'Ratite' birds, it is 

 obviously untrue as regards the genus Rhea. In the other genera, an answer is less 

 easy, audits nature must depend upon what is meant by the term 'lower larynx.' 

 If the presence of semi-rings externally, and of a membrana tympaniformis internally, 

 forming the walls of the bronchi, and of vocal chords developed in the interior of 

 those tubes, be held to be sufficient to characterize a ' syrinx,' then it will be incor- 

 rect to say that the Ratite birds have no voice-organs. As I have shown, all these 

 three structures are present, variously developed, in the genera in question, together 

 with at least a rudiment of a membrana semilunaris" 



