METHODS AND CHANNELS OF INFECTION. 539 



nature of foods which are taken into the body. Altered metabolism may 

 result in muscular weakness, delirium, pain and loss of appetite together 

 with vomiting, diarrhoea, disturbance of intestinal absorption and the 

 digestive juices. The fats and carbohydrates, first, and then the pro- 

 teins are rapidly used up, producing changes in the respired air and in 

 the urine and faeces. Infectious microorganisms may not only interfere 

 with the normal metabolism of the body but also alter the composition 

 of the substances taken into the body producing abnormal compounds 

 which have no nutritive value on absorption or toxic substances related 

 to ptomains, and leucomains. 



Attendant upon the changes in metabolism usually there occurs fever 

 in all infectious diseases. It is probable that the fever is the result of the 

 protein products of the infecting microorganisms or the disintegration 

 of the protein products of the body due to the toxic action. It is evident 

 that the fever-producing substances, in certain infectious diseases, act 

 in a very characteristic manner as is demonstrated by the so-called 

 typical fever curves. It seems to have been demonstrated that fever is 

 a good sign and that it is indicative of the reaction of the body to the 

 toxins of the infecting agents. It has also been shown that the fall of 

 fever in certain infections is attendant upon the formation and saturation 

 of the body fluids with antibodies. 



Blood-forming Organs.- There are usually changes in the blood- 

 forming organs in most all types of infection. The spleen frequently 

 shows enlargement. This is probably due to the disintegration and 

 deposition there of red corpuscles and the action of toxins. The endothel- 

 ial cells and leucocytes of the spleen are actively phagocytic. The 

 marrow, particularly the fatty marrow, shows large numbers of myelocytes 

 of the neutrophile type and becomes lymphoid in nature in a large 

 number of infections. The lymph glands frequently show endothelial 

 proliferation. 



Parenchymatous Tissues. All sorts of degenerations of the kidneys, 

 heart, liver and some of the other organs frequently occur in infections. 

 Amyloid formation and necrosis sometimes occur. Many of the toxins 

 have special affinities for tissues, such as the tetanus toxin for nerve tissue, 

 and produce changes in them. It is possible also that the fever is respon- 

 sible for a certain portion of the changes in the parenchymatous organs 

 in infections. 



Epithelial and Endothelial Tissues. In certain infections, as for example 



