PARASITES AND DISEASE (VEGETABLE PARASITES) 171 



the face this process produces a peculiar appearance 

 termed facies leontina. The mucous membranes may 

 be similarly affected and blindness may occur from in- 

 volvement of the conjunctiva and cornea, or loss of 

 voice and suffocation from involvement of the larynx. 

 Ulcer ations may lead to the loss of toes or fingers. In 

 the anesthetic form there is almost entire absence of the 

 deformities seen in the tuberculous variety of the disease. 

 There may, however, be in this form maculae and pem- 

 phigus-like bullae of the skin which may ulcerate, thus 

 leading to deformity and contractions or loss of fingers 

 and toes. 



Morbid Physiology. The alterations of function in this 

 disease are entirely local, as there seems to be no tox- 

 emia present. Secondary lesions may occur in internal 

 organs liver, spleen, testes, lungs, etc. which are 

 similar to the skin lesions. The anesthetic variety lays 

 the parts liable to various injuries from trauma, freezing, 

 burns, etc., because of the loss of sensation. 



PLAGUE 



Definition. An acute infectious disease caused by the 

 Bacillus pestis, characterized by inflammation of the 

 lymphatic glands, pneumonia, and hemorrhages. 



Etiology. Filth, squalor, and poverty undoubtedly 

 contribute to the existence and spread of the disease. 

 Infection, especially in the pneumonic type of the disease, 

 may occur by direct dissemination of the germ by in- 



