100 



BACTERIOLOGY. 



mouth or in the throat. It starts as a nodule, hard 

 at first, but later undergoes softening and finally sup- 

 purates, causing a discharging sinus. Infections of 

 the skin, lungs, intestines, and appendix have been de- 

 scribed. The parasite is supposed to enter the body 



Fig. 12. Actinomyces hominis (lung). X 350. 

 (Lenhartz-Brooks.) 



in grain, oats, barley, or rye, and in cattle from hay 

 or straw. 



The disease is not highly infectious, and all 

 danger is removed by careful disinfection of the dis- 

 charges containing the pus. 



YEASTS. 



Yeast-cells are much larger than bacteria; they 

 are oval in shape and have a thick cell -membrane. 



