144 A MANUAL OF VETERINARY PHYSIOLOGY 



tory sound is weaker and shorter than the inspiratory — that 

 is to say, the sound is not continued to the end of expiration, 

 but dies away before that is reached. The expiratory murmur 

 immediately follows the inspiratory without a pause, but there 

 is a marked pause between the end of one expiration and the 

 beginning of the next inspiration. 



The ordinary murmur is best heard where the chest wall is 

 thin ; if the ribs be covered with fat or any great thickness of 

 muscle, the sound may be entirely lost. It is also important 

 to note that there are some chests perfectly healthy where, for 

 no apparent reason, the respiratory murmur is obscure or even 

 undetectable. 



