I40 MANUAL OF BACTERIOLOGY. 



CHAPTER IV. 

 THE BACTERIA OF THE NORMAL HUMAN BODY. 



The numerous solid tissues and organs of the human body, 

 the fluids circulating in the interior like the blood and lymph, 

 and the cavities that have no connection with the outer world, 

 are entirely free from bacteria.* So also the maxillary, eth- 

 moidal and frontal sinuses, middle ear,t urinary bladder, uterus 

 and Fallopian tubes, and to a less extent the lungs J and gall- 

 bladder, § although having external connections, are usually 

 sterile when in a healthy condition. When bacteria do enter the 

 tissues from any of the surfaces their progress is checked by 

 means of the activities of the cells or fluids of the body, and if 

 they succeed in penetrating to apy considerable distance their 

 advance is usually arrested by the nearest group of lymph-nodes, 

 which appear to be important safeguards for preventing the 

 dissemination of bacteria throughout the body. As a rule, the 

 secretions of the mucous membranes are inimical to bacteria. 



The skin, || as might be expected, is liable to have upon it 



* This view is not upheld by the experiments of Ford, who found small num- 

 bers of bacteria in the normal organs of rabbits, cats and dogs in the majority 

 of those examined. The species of bacterfa obtained were mostly common 

 saprophytes, and to some extent constant in the same kind of animal. Journal 

 of Hygiene. Vol. I. igoi. 



t Calamida and Bertarelli. CentralblaUjiir Bakteriologie. Vol. XXXII. 1902. 

 Orig. p. 428. Torne. Ibidem. XXXIII. 1903. p. 250. Hasslauer. Ibidem. 

 Ref erate. XXXII, p. 1 74. An examination of these articles will show that in- 

 vestigators disagree somewhat, with regard to the sterility of these cavities. 



t See Wadsworth. American Journal Medical Sciences. May, 1904. 



§ See Bacteriology of the Gall-bladder and its Ducts. America-n Journal 

 Medical Sciences. Vol. CXXIII., p. 372. 



II Sabouraud. La Peau Humanie, etc. Bulletin de V Inslitul Pasteur. II. 

 1904. Pages 233, 282. 



