0R.\ 



ORN 



ligation or analysis of such bodies are 

 proximate or ultimate ; tlie former 

 when the parts are merely separated 

 by solvents, as water, alcohol, ether, 

 and acids ; the latter when the ele- 

 mentary composition is ascertained. 

 Carbon, hydrogen, oxygen, and nitro- 

 gen, combined in bin;iry, ternary, or 

 quarternary compounds, with a small 

 amount of saline matters, form the 

 majority of organic bodies ; sulphur 

 and phosphorus are present in a few 

 only. The modern process of organic 

 analysis is briefly described in Kane's 

 and in Graham's Chemistr}'. These 

 manipulations require great experi- 

 ence and skill. Vegetable tissues are 

 distinguished from animal by the 

 great amount of nitrogen in the latter. 



ORGANIC DISE.\SE. Disease 

 attended with an alteration of the 

 structure of a viscus or organ- 



ORGANIC REMAINS. Fossils. 



ORGANIZATION. The process- 

 es by which an organized body is 

 formed ; also the totality of the parts 

 which constitute, and of the laws 

 w'hich regulate, an organized body. 



ORGANOGRAPHY. A descrip- 

 tion of tlie structure of plants. 



ORLO. The plinth to the base of 

 a column or pedestal. 



ORNITHICNITES (from opvic, a 

 bird, and ixvoc, a trace). Certain 

 marks in the new red sandstone, sup- 

 posed to be bird tracks. 



ORNITHOLOGY (from opvic, a 

 bird, and Zojof, a description). The 

 science which teaches the natural 

 history and arrangement of birds. 



" The subdivision of the class of 

 birds is by no means so clearly indi- 

 cated by either external or anatomi- 

 cal characters as that of mammals, 

 and the systems of ornithology pre- 

 sent, in consequence, greater dis- 

 crepancy. 



" In the quinary arrangement of 

 birds, proposed by Mr. Vigors, there 

 may be traced a similar principle to 

 that which guided Nitzsch in his ter- 

 nary classification. Thus, the first 

 order {Rnptores, Virg ) includes the 

 birds which soar in the upper regions 

 of the air, which build their nests and 

 rear their young on the highest rocks 

 938 



and loftiest trees. The second ordei 

 {Inccssorcs) includes the birds which 

 aflecl the lower regions of the air, and 

 which are peculiarly arboreal in their 

 habits ; whence the name of perch- 

 ers. The third order corresponds 

 with Nitzsch's Avcs terrcstrcs, and is 

 termed Rasorcs. If the aquatic birds 

 of Nitzsch be divided into those 

 which frequent the fresh waters, and 

 are restricted to wading into rivers, 

 lakes, &c., in search of their food, 

 and those which have the power of 

 swimming or diving, and, for the 

 most part, frequent the ocean, we 

 shall then have the two remaining 

 orders of the quinary arrangement, 

 viz., Grallatores and Natatorcs. The 

 chief merit of this arrangement is its 

 aim to express the natural affinities, 

 and their circular progression in the 

 whole and in the several parts. 



" Linneeus and Cuvier have six or- 

 ders of birds, which are character- 

 ized as follows by the latter nat- 

 uralist : 



" Of all classes of animals, that of 

 birds is the most strongly character- 

 ized ; that in which the species bear 

 the greatest mutual resemblance, and 

 which is separated from all others by 

 the widest interval. Their system- 

 atic arrangement is based, as in the 

 mammalia, on the organs of mandu- 

 cation, or the beak, and in those of 

 prehension, which are again the beak, 

 and, more particularly, the feet. 



" One is first struck by the charac- 

 ter of webbed feet, or those wherein 

 the foes are connected by membranes 

 that distinguish all swimming birds. 

 The backward position of their feet, 

 the elongation of the sternum, the 

 neck, often longer than the legs, to 

 enable them to reach below them, the 

 close, glossy plumage, impervious to 

 water, altogether concur with the 

 feet to make good navigators of the 

 Palmipedes. 



"In other birds, which have also 

 most frequently some small web to 

 their feet, at least between the two 

 external toes, we observe elevated 

 tarsi ; legs denuded of feathers above 

 the heel joint ; a slender shape ; in 

 fine, all the requisites for wading in 



