ZOOLOGY. 



TTof, fruit). The name given to certain 

 organized bodies which have been vari- 

 ously considered as animals, as plants, 

 and as partaking of the characters of each 

 of these divisions of organized beings. 

 They are found among the lower forms of 

 alga of botanists, as the diatoma, the 

 fragillaria, &c. 



ZOO'LOGY {^Mov, an animal, Xoyo?, a 

 description). That branch of Natural 

 Science which investigates the nature, 

 properties, and classification of the sub- 

 jects of the Animal Kingdom. Under 

 the term Animal Kingdom, a table is 

 given of the terras employed by different 

 writers in classifying these subjects. 



1. Divisions of Aristotle. Aristotle's 

 primary divisions were derived from the 

 presence and the (supposed) absence of 

 hlood in animals, which were, therefore, 

 termed enaima {hv, in, ai/xa, blood) or 

 sanguineous, including beasts, birds, 

 reptiles, and fishes ; and anaima (a, priv. 

 ai/xa, blood) or ex-sanguineous, including 

 all the lower species. The subsequent 



discovery of white blood in animals, and 

 the substitution of the terms " red- 

 blooded " and white-blooded " for the pri- 

 mary divisions of Aristotle, were steps in 

 the progress of improvement. 



2. Divisions of LinncEus. In the "Sys- 

 tema Naturae " the natural divisions of 

 the Animal Kingdom are indicated by 

 internal structure. Thus, with a bilocular 

 heart with two auricles, and warm, red 

 blood, we have viviparous animals in the 

 Mammalia, oviparous in the Birds. With 

 a unilocular heart with one auricle, and 

 cold, red hlood, we have, furnished with 

 arbitrary lungs, the Amphibia, with ex- 

 ternal gills, the Fishes. With a unilocu- 

 lar heart with one auricle, and cold, 

 white circulating fluid {sanies), we have, 

 furnished with antennae, the Insects, with 

 tentacula, the Worms. 



3. Divisions of Cuvier. The following 

 table exhibits Cuvier's fourfold division 

 of the Animal Kingdom, together with 

 the classes, sub-classes, orders, and an 

 example of each division : — 



Div. I.— VERTEBRATA. 



Animals which have an internal skeleton, supported by a spine. 



Order. 



Example. 



