190 APPENDIX. 



The Mouth. The mouth is a favorite seat for the development 

 of bacteria. The alkaline saliva, the particles of food left in 

 the teeth, the decayed teeth themselves, all furnish suitable 

 soil for their growth. 



Quite a number of germs have been isolated and their prop- 

 erties partly studied. Many have some connection with the 

 production of caries of the teeth, as Miller has well shown in 

 his careful studies. The Leptothrix buccalis, found in nearly 

 all mouths, is a long chain or filamentous bacillus which stains 

 blue with iodin. It was formerly considered the cause of tartar 

 on the teeth. 



The Spirillum sputigenum, Spirochaeta dentium, Micrococcus 

 gingivse pyogenes, Bacillus dentalis viridans, B. pulpse pyogenes, 

 Microccocus of sputum-septicaemia, and M. salivarus septicus 

 are a few of the germs cultivated by Miller and Biondi from 

 the mouth. Besides these, the pneu mo-bacteria, diphtheria 

 bacillus, and tubercle bacillus are often met with, the first two 

 in the mouths of healthy persons. The expired air in quiet 

 respiration is free from bacteria, but in coughing, sneezing, etc., 

 large numbers of organisms are violently ejected and the 

 atmosphere about tubercular patients is always saturated with 

 tubercle bacilli. 



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

 organisms were found, but quite a number of non-pathogenic 

 ones. In affections of the ear the pneumo-bacillus and the 

 Stnphylococcus pyogenes are most frequent. 



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 coryzse, Micrococcus nasalis, Bacillus foetidus 

 ozaenae, B. striatus albus et flavus, B. capsulatus mucosus, and 

 Vibrio nasalis are some of the organisms described 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 dimin- 

 ished in quantity or absent altogether, the conditions for the 



