THE ANATOMY OF THE DOMESTIC ANIMALS 



INTRODUCTION 



Anatomy is the branch of biological science which deals with the form and 

 structure of organisms, both animal and vegetal. It is therefore in close correlation 

 with physiology, which treats of the functions of the body. 



Etjrmologically the word "anatomy" signifies the cutting apart or disassociat- 

 ing of parts of the body. In the earlier phases of its development anatomy was 

 necessarily a purely descriptive science, based on such observations as were possible 

 with the unaided eye and simple dissecting instruments — the scalpel, forceps, and 

 the like. At this time, therefore, the term adequately expressed the nature of the 

 subject. But as the scope of the science extended and the body of anatomical 

 knowledge grew, subdivisions became necessary and new terms were introduced to 

 designate special fields and methods of work. With the introduction of the mi- 

 croscope and its accessories it became possible to study the finer details of structure 

 and minute organisms hitherto unknown, and this field of inquiry rapidly developed 

 into the science of microscopic anatomy or histology as conventionally disting-uished 

 from macroscopic or gross anatomy. In the same way the study of the changes 

 which organisms undergo during their development soon attained sufficient im- 

 portance to be regarded on practical grounds as a separate branch known as 

 embryology.! 



Comparative anatomy is the description and comparison of the structure of 

 animals, and forms the basis for their classification. By this means — including 

 extinct forms in the scope of inquiry — it has been possible to show the genetic 

 relationship of various groups of animals and to elucidate the significance of many 

 facts of structure which are otherwise quite obscure. The deductions concerning 

 the general laws of form and structure derived from comparative anatomical 

 studies constitute the science of morphology or philosophical anatomy. The 

 morphologist, however, deals only with such anatomical data as are necessary to 

 form a basis for his generalizations. The anatomical knowledge required in the 

 practice of medicine and surgery is evidently of a different character and must 

 include many details which are of no particular interest to the morphologist. 



Special anatomy is the description of the structure of a single type or species, 

 e. g., anthropotomy, hippotomy. 



Veterinary anatomy is the branch which deals with the form and structure of 

 the principal domesticated animals. It is usually pursued with regard to pro- 

 fessional requirements, and is therefore largely descriptive in character. As a 

 matter of convenience, the horse is generally selected as the type to be studied in 

 detail and to form a basis for comparison of the more essential differential characters 

 in the other animals. 



Two chief methods of study are employed — the systematic and the topo- 

 graphic. In the former the body is regarded as consisting of systems of organs or 



1 This term is usually limited in its application to the earlier phases of development during 

 which the tissues and organs are formed. The term ontogeny is used to designate the entire 

 development of the individual. The ancestral history or phylogeny of the species is constituted 

 by the evolutionary changes which it has undergone as disclosed by the geological record. 

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