THE AUTOGENOUS DISEASES. 485 



doubtedly is the explanation of the frequently observed fact that 

 injury to some part of the body leads to tubercular lesions in that 

 locality. In this way we can account for tuberculosis of the hip 

 joint, of the spine, and of the meninges of the brain. These illus- 

 trations must suffice to show the difference between auto-infection 

 and auto-intoxication. 



Some writers are inclined to place under the head of auto-intoxica- 

 tions all those diseased conditions in which no lesions can be detected 

 either macroscopically or microscopically, while on the other hand, 

 they exclude from the list of autogenous diseases all those disorders 

 which are accompanied by lesions. This, in our opinion, is plainly 

 unscientific, and, indeed, the error of such a position needs only to be 

 pointed out in order to be plainly understood. The endogenous 

 poisons may induce lesions which are quite as extensive and quite 

 as marked as those which result from the ectogenous toxins. For 

 instance, recent researches have shown that normal, sterile bile 

 when introduced into the pancreatic duct and brought in contact 

 with the tissue of this gland causes most marked necrotic changes ; 

 indeed, it is doubtful whether or not we have among the bacterial 

 toxins any substance which will cause more marked morphological 

 changes in any tissue than that induced by normal bile when 

 brought in contact with the pancreas. It must be evident, there- 

 fore, that we cannot exclude from the autogenous diseases all of 

 those which show tissue changes. Indeed, it is probable that there 

 is no disease which is unaccompanied by morphological changes in 

 the cells in some part of the body. These alterations may be so 

 slight that they have escaped detection, but it certainly is true that 

 the number of diseases unaccompanied by morphological changes 

 grows less each day. 



As has already been stated, we have not as yet sufficient scientific 

 data to enable us to attempt even a provisional classification of the 

 autogenous diseases. However we may point out certain facts con- 

 nected with this subject. 



1. The digestive organs may but imperfectly perform their func- 

 tion, and the products of their incomplete action may be absorbed 

 and may lead to more or less disturbance in certain organs of the 

 body. Moreover in such a case as this every part of the body will 

 suffer more or less from insufficient nutrition due to the fact that 

 properly prepared pabulum is not brought within reach of the cellu- 

 lar elements. That imperfectly digested proteids, and in fact certain 

 proteids wholly undigested, may be absorbed, is a well known fact. 

 To what extent the absorption of undigested proteids may take 

 place in the animal body and how much harm can be wrought in 

 this way, we are not able to say. It is more than probable that the 

 great susceptibility of the infant to bacterial products formed in 

 milk is due to the fact that during this period of life the intestinal 



