10 The Farmer's Veterinary Adviser. 



dance of vitally potent white blood-globules and tissue-cells. 

 This pns-forming action of these bacteria explains the grea'fi 

 difference in results in wounds exposed to the air and those 

 in the interior of the body and far removed from air and its 

 floating bacteria. A broken bone, with no wound in the 

 skin and little injury to parts around the fracture, is rsadily 

 repaired, without any formation of pus, if merely kept still 

 and immovable ; whereas a broken bone, continuous witli a 

 wound through the skin, always tends to form pus and is 

 extremely dangerous even to life. The tendency of every 

 open sore is to form pus on its surface, but this may be 

 arrested and prevented by a free use of disinfectants and a 

 covering which shall arrest and filter out the germs. Simi- 

 larly in an abscess the injection of disinfectants, without the 

 formation of any perceptible permanent opening to the outer 

 air, will put a stop to the pus-formation. The subjection of 

 an inflamed part to the control of these pus-forming bacteria 

 is dependent on the lowered vitality and power of resistance 

 of the inflamed tissues, and of the white cells of their circu- 

 lating blood. Healthy parts can successfully resist them, 

 though they are constantly present in surrounding air and 

 on objects, but in this, as in all other cases; of bacterial in- 

 fection, so soon as the tissue is injured, inflamed, and lowered 

 in its power of vital resistance, the pyogenic bacteria assail 

 it successfully. Hence, too, the more abundant exudations 

 of lymph, the centres of which are farthest removed from 

 the healthy tissues, and from the influence of their vital re- 

 sistance, are the most prone to suppuration. That the germs 

 can make their way to such deep-seated exudations in the 

 substance of solid tissues is to be accounted for by their 

 gradual advance through the inflamed and weakened struct- 

 ures from the adjacent skin or mucous membrane, or in 

 some instances by reason of their presence in small numbers 

 in the blood. It is further noteworthy that those animals 

 in which suppuration does not occur readily are such as have 



