The Osseous System 329 



cessfuUy treated a penetrating fracture of the frontal bone, half an 

 inch in length and one eighth of an inch in width caused by a 

 butcher's knife which had been thrown at the animal. Part of the 

 brain substance, the size of a horse-bean, protruded through the 

 wound. The symptoms to which these injuries gave rise were: 

 partial paralysis of the right side but without loss of consciousness, 

 knuckling over of the knee whenever weight was put on that limb, 

 and aimless movements to the right in an irregular sort of circle. 

 The protruding portion of brain was removed, the skin shaved and 

 dressed antiseptically and the edges of the wound drawn tightly 

 together by silk sutures. Complete recovery ensued in a week. 



The great danger of penetrating fractures which are not of 

 sufficient extent to immediately cause death is the liability to intra- 

 cranial suppuration. Depressed fractures are always dangerous 

 through their causing compression of the brain. The cranial cavity 

 is completely filled by the brain, its meninges, blood vessels and 

 fluids. Any decrease in its capacity necessarily results in com- 

 pression of the contained organs. While it is known that the cerebro- 

 spinal fluid under the influence of pressure is forced into the spinal 

 canal, thus permitting of a certain degree of accommodation to new 

 conditions, experiments have established the fact that compression 

 of the brain by one-sixth of its volume of any material is fatal, and 

 attended by very serious results under much less. Pagenstecher 

 studied the effects of brain-compression produced by injecting wax 

 between the dura mater and cranial vault. His researches showed 

 that the capacity of the skull could be diminished about one-thirtieth 

 without inducing cerebral phenomena. 



Depressed fractures become evident through change of contour 

 and by examination with finger and eye. The symptoms appear 

 concurrently with the receipt of the injury. Owing to the increase 

 of intracranial pressure the blood flow is retarded and together 

 with the direct influence of the compressing body there ensue either 

 restlessness, stupor, or coma, with slow respiration and hemiplegia 

 or limited paralysis of certain groups of muscles. In one of Moel- 

 ler's cases the animal remained deaf during the rest of its life, and 

 subsequently it was demonstrated at the necropsy that the temporal 

 bone had sustained marked injury. 



Uebelen treated a Pointer which was in a comatose condition. 

 The kick of a horse had shattered the whole of the left side of the 



