ACTINOMYCOSIS. 
9 
lining the lips, mouth, pharynx and nostrils, or in fact, any 
part of the digestive or respiratory passages. 
It has been shown that it may exist harmlessly in large 
numbers in the tonsilar glands of the pig probably waiting 
for a casual abrasion of the mucous membrane, in order that 
it may rapidly develop in the tissues beneath. Such an injury 
' may be inflicted in various ways, and very likely by the food 
upon which the animals most liable to the disease are fed. 
It has been noticed by some practitioners in England that 
the malady is most frequent after cattle have been fed on bar¬ 
ley straw and chaff, and this may not only injure the mouth 
but serve also as the vehicle for the transmission of the fun¬ 
gus, straw being so often mouldy and infested with vegetable 
parasites of various kinds. 
After having once entered the animal’s body, the extension 
of the fungus is progressive by means of its spores, which are 
disseminated, localize themselves, and produce the character¬ 
istic changes in their surroundings. These spores may find 
their way into the oesophagus, stomach, intestines, bronchi, 
lungs, or in fact, almost any of the internal organs or tissues, 
and there produce the disease unless, as sometimes happens, 
spontaneous recovery takes place, owing to the fungus losing 
its vitality through diminished nutritive supply from retrac¬ 
tion of the connective tissue surrounding it, and its becoming 
encapsuled in lime salts. 
As I have just stated, the fungus after gaining access to 
the system may become localized and produce the character¬ 
istic lesions of the disease in almost all parts of the animal’s 
body. The different situations in which it has hitherto been 
observed, are the bones of the jaw, both upper and lower, the 
submaxillary space, and region of the parotid gland and 
throat, the tongue, nasal chambers, pharynx, larnyx, oesopha¬ 
gus, stomach and intestines, the lungs, the skin, and the sub¬ 
mucous, and intermuscular connective tissue. 
It is generally supposed that the jaw bones are the parts 
most often attacked by the disease, but in the majority of 
cases which I have had an opportunity of seeing, the regions 
of the parotid gland and throat have been the parts most 
