Ornithology, — Technical terms* 141 



10. Tlic vent feathers and under-tail coverts, that extend from the 

 anns or vent to the tail underneath. These feathers are much longer in some 

 tribes of Birds than others. Those that have a constant habit of flirting by 

 their tails — like, for example, the Rallus Carolinus, and several species of 

 small shore Birds— have the vent feathers unusually well developed. 



The tail feathers are various in size and numbers, and are generally the 

 most ornamental part of a Bird. The tail performs the most necessary office 

 in the navigation of the Bird through the air ; in fact, it is the rudder by 

 which the course of the Bird is determined, and acts in concert with the will 

 of the Bird as freely as a ship obeys her helm. 



11. Loral space. — The space between the bill and eye. 



12. Frow5.— The forehead. 



13. Corona.— Crown of the head. 



14. Occiput. — The hind part of the head, 



15. Flexure. — Bend of the wing. 



16. Tarsi. — Shanks of legs. 



17. r^im.— Thigh. 



The upper and lower bills are called the superior and inferior maxilla, 

 or upper and lower mandibles. 



Iris— irides.— The colored circle surrounding the pupil of the eye. 



3'lentu7n.—The chin. 



Guttur. — The throat. 



Collum. — The neck. 



Pectus. — The breast. 



In measurement, the total length means from point of the bill to the end of 

 middle tail feathers. Length of the ivings means from the bend of the wing 

 to the end of the longest quill feather." 



The mirror, speculum or Beauty spot, is a space on the wings of some 

 epecies with brighter colours than the other parts of the wing. 



The length of the wing is generally measured from the tip of one wing 

 to the tip of the other, and the two dimension are simply expressed in figures 

 thus, 24)2) ^^}'2 j "t^^ fii'st indicating the length from the bill to the tail, and 

 the latter the length of the expanded wings. 



The above are nearly all the technical terms used in describing birds, 

 and after a few attempts at their application to specimens, they will become 

 fixed m the memory, and give no further trouble. There are many systems 

 of classification proposed by various authors, and to reconcile them all with 

 each other would be impossible ; in fact most of them are considered by the 

 best naturalists to be defective, and need not be studied until after some 

 knowledge of the species, and genera has been acquired. 



LinnaBus, in his Sijstema Natures, divides the class of Birds into six 

 orders. Blumenbach makes nine orders. Cuvier makes six. M. Vieillot, 

 a celebrated French Ornithologist, five. Mr. N. A. Vigors, five. M. C. 

 J. Temminck, in his Manuel d' Ornithologie, sixteen; and Professors 

 Agassiz & Gould, in the system published in the second article of this Jour- 

 tisl, only four orders. 



