DOMESTIC ANIMALS. 131 



character. When this condition exists the case is incur- 

 able. This permanent growth is formed by the organiza- 

 tion of the first exudate, in the same manner as granula- 

 tion tissue is formed. DR. HEABD'S CONDITION POWDERS 

 are an excellent preventive of a return of the malady. 



PURPURA HAEMORRHAGICA, SOMETIMES 

 CALLED BIO HEAD 



Somewhat closely related to the last described disease 

 is that of Purpura Haemorrhagica, when we have swell- 

 ings suddenly appear in different parts of the body. 

 They are very frequent around the head, the lips are 

 sometimes enormously swollen, the walls of the nostrils 

 are sometimes so much enlarged that the animal is 

 threatened with suffocation, and the eyelids are often 

 enormously swollen. The limbs, too, are frequently the 

 parts where large swellings suddenly appear. To deter- 

 mine the exact change in th^p constitution of the animal 

 exhibiting these local evidences of disease seems to be 

 a question of great difficulty wtth pathologists. It seems 

 to me that writers on this disease have unnecessarily 

 complicated the subject, especially that part of it relat- 

 ing to causes. The swellings are undoubtedly due to 

 an escape of some of the blood elements from the vessels 

 that normally carry the blood. Now, if we remember 

 that the blood is a fluid containing an enormous num- 

 ber of individuals perfectly formed, many of them lead- 

 ing an independent existence in that fluid in the same 

 manner as do some of the animalculae in water, having 

 the power of locomotion, digestion, respiration, and 

 propagation, apparently independent of each other, in- 

 dividually subject to the change known as death, which 



