ORGANS AND CAVITIES OF THE HUMAN BODY 259 



patients is often saturated with tubercle bacilli. The bac- 

 teria may enter the system from the pharynx to the tonsils 

 and cervical glands by means of the lymphatics. 



Ear. In the middle ear of new-born infants no pathogenic 

 organisms have been found, but quite a number of non- 

 pathogenic ones. In affections of the ear the pneumobacillus 

 and the Staphylococcus pyogenes are most frequent. 



When the streptococcus is present in acute suppurations, 

 there is great danger of mastoiditis. In chronic otitis the 

 gas-forming bacteria, as well as Bacillus pyocyaneus, is often 

 found. 



Nasal Cavity. The nasal secretion, containing as it does 

 dead cells and being alkaline in reaction, forms a good soil for 

 the growth of germs. 



Diplococcus coryzae, Micrococcus nasalis, Bacillus fcetidus 

 ozaenae, Bacillus striatus albus et flavus, Bacillus capsulatus 

 mucosus, and Vibrio nasalis are some of the organisms de- 

 scribed by various observers. 



Stomach and Intestine. The secretion of the stomach 

 is in its normal state not a favorable soil for the development 

 of bacteria, yet some germs resist the action of the gastric 

 juice and flourish in it. When the acids of the stomach are 

 diminished in quantity or absent altogether, the conditions 

 for the growth of bacteria are more favorable. The alimen- 

 tary canal of the new-born infant is sterile, but in a few 

 hours after birth microorganisms begin to appear. 



Some gastric bacteria normally present are Sarcina ventric- 

 uli, Bacterium lactis aerogenes, Bacillus subtilis, Bacillus 

 amylobacter, Bacillus megaterium. 



The intestinal organisms are more numerous, and the 

 mucous lining of the intestines and the secretions there present 

 are favorable to germ-growth. 



Bacillus geniculatus Boas considers a sign of carcinoma of 

 the stomach, and is always present, he claims, when the con- 

 tents contain lactic acid. 



Some investigators consider digestion dependent on micro- 

 bic activity, but experiments with animals have shown that 



