THE NERVOUS SYSTEM. 385 



dently found in separating the jaws, and in performance of 

 the voluntary movements in general. The disinclination 

 to feed is the first matter which directs attention to the 

 case, but there is no concomitant fever. There is a 

 straddling gait, due to inflexibility of the hind limbs. 

 Attention is directed to the mouth to determine the cause 

 of refusal of food, and it is found that by this time the 

 jaws are locked. Usually there is a flow of saliva of a 

 foetid character from the mouth when the lips are separated. 

 Soon the appearance of the patient becomes characteristic ; 

 there is a marked condition of the muscles, due to rigi- 

 dity, the tail is slightly straightened, the haw protruded, 

 and the animal moves '^ all of one piece.'^ If the haw be 

 not protruded it will do so when the head is raised. The 

 muzzle is extended forwards, and there is obstinate con- 

 stipation. The animal sometimes tries to feed, and 

 succeeds in sucking up a small quantity of fluid ; he some- 

 times falls and continues in the recumbent position, but 

 as often stands persistently. Respiration is materially 

 interfered with by the contraction of the inspiratory 

 muscles, but the diaphragm for a long time retains its 

 activity. That the sympathetic system is involved is 

 inferred from the state of the bowels ; in some cases this 

 may be primary, and the disease of the cord secondary. 

 As a general rule, the reverse is the case. Sometimes 

 the disease proves rapidly fatal, and causes death on the 

 second or third day ; if the patient lives to the sixth day 

 some hopes of cure may be held out, but the prog- 

 nosis is never very favorable, for we are working very 

 much in the dark in treating tetanus. In some cases it 

 is directly traceable to a wound either in the suppurative 

 or cicatrising stage, when it is supposed that some nerve- 

 fibre is entangled in the scar or otherwise disordered. Of 

 these wounds the most frequent are surface-grazes, those 

 produced in castration, and pricks in shoeing. Owing to 

 the frequency of the latter, it is said to be most prevalent 

 in working oxen. The idiopathic forms are attributable 

 to exposure to cold and sudden changes of temperature, 

 especially when the skin is heated. Thus, it is some- 



25 



