2 COMPARATIVE ANATOMY. 



Anatomy may be divided into general and special Anatomy. 

 General Anatomy has to do with the fundamental forms of animal 

 organisms (Promorphology), and the morphological phgenomena 

 which arise from them. Special Anatomy takes for its object the 

 oro-anological composition of the animal body. Histology, or 

 microscopic Anatomy, forms one of its branches, being the study 

 of the elementary organs of the animal body. Embryology 

 explains, by tracing their gradual development, the complications 

 of the external and internal organisation, and, in fact, deduces 

 them from simpler conditions. The changes in organisation can be 

 followed out in the embryonic life of the individual, and also in the 

 continuous series of organisms. The discipline ordinarily known 

 as Embryology deals with the former; and as Ontogeny (or the 

 development of the individual) is contrasted with Phylogeny (or 

 the development of the phylum) . As the latter includes the earlier 

 and no longer existent conditions of animals, it also embraces 

 Palseozoology. It is the history of the development of the series 

 of organisms in their geological succession. 



§ 2. 



Since Anatomy has for its object the composition of organisms, 

 it may be considered as the doctrine of structure, and is divided, 

 according to the different points of view from which structure 

 itself may be regarded, into several divisions. When the com- 

 position of the body itself, its forms, and the relations of the separate 

 organs are taken as its scope, it is known as descriptive Anatomy, 

 for it describes the objects examined, without drawing any further 

 conclusions from them. Anatomical fact is the aim of the investiga- 

 tion, and empiricism satisfies this aim. Owing to its relations to 

 medicine, and so to practical requirements, the descriptive Anatomy 

 of the human organism, so far as it is restricted to a special series 

 of facts, has become developed into a special branch, which, as 

 Anthropotomy, is put side by side with the similarly descriptive 

 Zootomy. The two differ only in their subject-matter, and not in 

 their treatment of it, for both are analytical. In proportion as 

 either abstains from drawing conclusions from its series of facts, 

 and giving these the value of abstractions, is it wanting in the 

 character of a science ; for a science is constituted neither by an 

 extensive range of observations, nor by the complication of the 

 methods by means of which such observations are made. A critical 

 appreciation of the scientific import of any branch of study has, 

 therefore, little to do with the mechanical apparatus of investiga- 



