264 BOVINE PATHOLOGY. 



structure is laminated, and almost invariably tliey are 

 arranged around a small piece of metal or a stone which 

 has been swallowed as a nucleus. These bodies have little 

 pathological importance ; they have been known to choke 

 an animal during regurgitation. They are passed up into 

 the mouth, and thus rejected when of moderate size. It 

 is doubtful if they ever pass from the rumen into the 

 omasum. Probably they do not, though '^ hair balls " are 

 found in the abomasum, as we shall see. Sometimes they 

 are coated with a thin layer of lime salts, with which they 

 are more or less impregnated throughout. Finally, they 

 are sometimes present in very young animals. They are 

 termed ^gagropiles. 



Hernia op the Rumen and Reticulum sometimes occurs, 

 sjid fistula of the rumen have enabled Continental observers, 

 more especially Flourens and Colin, to accurately deter- 

 mine the conditions of this viscus and its contents during 

 rumination. 



Impaction op the Omasum, known as " Staggers/' 

 " Vertigo/' " Fog sickness/' ^^ Olue hound/' &c. — This is 

 by most practitioners considered a very frequent and 

 serious disorder, but Professor Williams has thus expressed 

 himself in his ' Principles and Practice of Veterinary 

 Medicine i' — " This is a very popular disease, some writers 

 ascribing every case of constipation to impaction of the 

 omasum, basing their conclusions upon the fact that the 

 contents of this viscus are in a dry and hard condition 

 when examined after death; but seeing that this is its 

 natural state, and that, when animals have died from what 

 appeared to be obstinate constipation, its contents have 

 been found moister than natural, I have arrived at the 

 conclusion that what is supposed to be impaction of the 

 third stomach is in reality an inflammation of the mucous 

 membrane of the true stomach — abomasitis, or true 

 gastric inflammation.^' Undoubtedly the professor is 

 right in denying that all cases of constipation depend 

 upon this condition, and he has done the profession good 

 service, by drawing attention forcibly to the fact that the 

 hard condition of food between the laminae of the omasum 



