128 PATHOLOGY. 



affected, or anatomically, according to tlie parts which they 

 invade. The simplest plan, however, seems to me to be that 

 adopted by Eeynolds, namely, the division of diseases into two 

 great groups. 



The first group includes those diseases in which the whole 

 organism appears primarily and prominently deranged, and the 

 second group those diseases in which special organs or systems 

 of organs are in like manner affected. The first group is divided 

 into two classes : — A, those in which the disease appears to be 

 developed by causes operating from without; and B, those in 

 which it depends upon change within the body. In the first 

 class we have those ciseases which are caused by atmospheric 

 influences, contagion, and other external causes ; and in the 

 second, hereditary diseases, rheumatism, rickets, and other 

 obscure bone diseases. 



The second group, or that in which special organs are diseased, 

 is again subdivided into many classes, consisting of diseases of 

 systems of organs, such as — A, diseases of the nervous system ; 

 B, diseases of the digestive system and its appendages ; C, 

 diseases of the circulatory system ; D, diseases of the respiratory 

 system; E, diseases of the urinary system ; F, diseases of the 

 reproductive system ; G, diseases of the locomotive system ; and 

 H, diseases of the cutaneous system. 



