e GENERAL CONSIDERATIONS 



moved, or it is transmitted through the medimn of oth%r organs, such as the 

 tendons and the aponeuroses. 



The central nervous organs — the nerves properly so called — belong to this group 

 of solid organs. The activity of muscles and the sensibility of limitary membranes 

 are due to them. 



With regard to the hollow organs, they are everywhere formed by an envelope 

 of smooth (or unstriped) muscular tissue, lined by an internal tegumentary or 

 mucous membrane. Examples : the bladder and stomach. There must also be 

 included the vessels formed by elastic and contractile membranes arranged as 

 canals, in which the blood and lymph circulate ; the glands, and, lastly, the serous 

 membranes which line the interior of the splanchnic cavities, cover the surface of 

 the organs contained in them, and the inner face of the articulations and synovial 

 sheaths. 



It is remarkable that, in the trunk, the bones form two superposed cylinders, 

 one of which lodges the organs of circulation, digestion, and respiration, and the 

 other the central nervous system (neural and luemal ajUnder). 



Apparatus. — Organs are very numerous in the animal economy, and in order 

 to study them profitably it is necessary to classify them in a methodical manner, 

 according to their physiological affinities. Consequently, there have been col- 

 lected into a single category all those organs which are destined to achieve the 

 same physiological finality, and to such a group has been given the name of 

 apparatus. 



Bichat has grouped the apparatuses according to the ultimate object of their 

 functions, and has thus formed two great categories : one, comprising the 

 apparatuses which maintain the individual {apparatuses of nutrition and relation) ; 

 the other, the apparatus destined for the preservation of the species {apparatus of 

 generation). 



We will describe these apparatuses in the following order : — 



1. Locomotory Apparatus ; 



2. Digestive Apparatus ; 



3. Respiratory Apparatus ; 



4. Urinary Depurative Apparatus ; 



5. Circulatory Apparatus ; 



6. Inner vatory Apparatus ; 



7. Sensory Apparatus ; 



8. Generative Apparatus. 



This description will be terminated by a brief notice of the evolution of ths 

 /(Btus^ and its appendages. 



