DIREASE3 OF THE NERVOUS SYSTEM. 107 



heat stroke should not be prepared for use as food. On account of 

 the fever with which the animal suffers, the flesh contains toxins that 

 may render it poisonous to the consumer. 



INJURIES TO THE SPINAL CORD. 



The spinal cord is liable to concussion from blows and falls, and 

 paralysis, to a greater or less extent, may be the result. Fracture, 

 with displacement of the bones (vertebrae) which form the spinal col- 

 umn, by compressing the spinal cord, produces paralysis, which varies 

 in its effect according to the part of the cord that is compressed. If 

 the fracture is above the middle of the neck, death soon follows, as 

 communication between the brain and diaphragm (the essential 

 muscle of inspiration) is stopped. When the fracture is farther 

 down in the neck, posterior to the origin of the phrenic nerve, the 

 breathing continues, but there is paralysis in all parts posterior to the 

 fracture, including the fore and hind legs. When the fracture is in 

 the region of the loins the hind legs are paralyzed, but the fore legs 

 are not. If the fracture is in, the sacrum (the division of the spinal 

 column between the loins and the tail), the tail alone is paralyzed. 



As a matter of course, when the back is broken there is no remedy ; 

 the animal should be killed at once. 



PARALYSIS. 



Paralysis, or loss of motion in a part, may be due to a lesion of the 

 brain, of the spinal cord, or of a nerve. It may also be caused by 

 reflex irritation. When the paralysis affects both sides of the body, 

 posterior to a point, it is further designated by the name paraplegia. 

 When one side of the body (a lateral half) is paralyzed, the term 

 hemiplegia is applied to the affection. When paralysis is caused by 

 a lesion of a nerve, the paralysis is confined to the particular part 

 supplied by the affected nerve. 



As already pointed out, paralysis may be due . to concussion of the 

 spine, fracture of a bone of the spinal column with consequent com- 

 pression of the spinal cord, concussion of the brain, or compression of 

 the brain. An injury to one side of the brain may produce paralysis 

 of the same side of the head, and of the opposite side of the body hemi- 

 plegia. Paralysis may occur in connection with parturient apoplexy, 

 lead poisoning, ergotism, etc. 



CONGESTION OP THE SPINAL CORD. 



Paraplegia, or paralysis of the rear part of the body, is the domi- 

 nant symptom in congestion or inflammation of the spinal cord. The 

 cause is not known, but the disease is probably due to chilling. It is 

 thought by some that some toxic influence (poison) may be responsi- 

 ble for its development. 



