PNEUMOGASTRIC NERVE. 469 



tion is a diminished frequency in the movements of respiration. This 

 diminution is frequently strongly marked from the first, the number 

 of respirations falling at once to ten or fifteen per minute, and be- 

 coming, in an hour or two, still farther reduced. The respirations 

 are performed easily and quietly ; and the animal, if left undisturbed, 

 remains usually crouched in a corner, without giving any special 

 signs of discomfort. If he be aroused and compelled to move 

 about, the frequency of the respiration is temporarily augmented ; 

 but as soon as he is again quiet, it returns to its former standard. 

 By the second or third day, the number of respirations is often 

 reduced to five, four, or even three per minute ; when this is the 

 case, the animal usually appears very sluggish, and is roused with 

 difficulty from his inactive condition. At this time the respiration 

 is not only diminished in frequency, but is also performed in a 

 peculiar manner. The movement of inspiration is slow, easy, and 

 silent, occupying several seconds in its accomplishment ; expiration, 

 on the contrary, is sudden and audible, and is accompanied by a well 

 marked expulsive effort, which has the appearance of being, to a 

 certain extent, voluntary in character. The intercostal spaces also 

 sink inward during the lifting of the ribs ; and the whole movement 

 of respiration has an appearance of insufficiency, as if the lungs 

 were not thoroughly filled with air. This insufficiency of respira- 

 tion is undoubtedly owing to a peculiar alteration in the pulmonary 

 texture, which has by this time already commenced. 



Death takes place at a period varying from one to six days after 

 the operation, according to the age and strength of the animal. 

 The only symptoms accompanying it are a steady failure of the 

 respiration, with increased sluggishness and indisposition to be 

 aroused. There are no convulsions, nor any evidences of pain. 

 After death the lungs are found in a peculiar state of solidification, 

 which is almost exclusively a consequence of this operation, and 

 which is entirely different from ordinary inflammatory hepatization. 

 They are not swollen, but rather smaller than natural. They are 

 of a dark purple color, leathery and resisting to the feel, destitute 

 of crepitation, and infiltrated with blood. Pieces of the lung cut 

 out sink in water. The pleural surfaces, at the same time, are bright 

 and polished, and their cavity contains no effusion or exudation. 

 The lungs, in a word, are simply engorged with blood and empty 

 of air ; their tissue having undergone no other alteration. 



These changes are not generally uniform over both lungs. The 

 organs are usually mottled on their exterior ; the variations in color 



