410 Anatomy Applied to Medicine and Surgery. 



the substance of the conjunctiva, is of a brighter color on 

 account of the facility of oxidation from its exposed posi- 

 tion. In cases of effusion of blood into the conjunctiva 

 from a purely local injury, if the conjunctiva be made to 

 glide over the sclerotic, the discoloration is seen to move 

 with it, since, as already stated, the effusion of blood is 

 into the structures of the conjunctiva, and not under it, 

 as it is in the case of an ecchymosis due t6 a fracture. In 

 the latter case, i.e., in fracture, not only is the effusion of 

 blood beneath, rather than in the conjunctiva, but it ap- 

 pears here before showing itself in the lower lid, and 

 further, the upper lid is not affected, in fracture of the 

 base, unless the fracture involve the orbital ridge as well 

 as the orbital plate. The total absence of ecchymosis, how- 

 ever, cannot exclude a basal fracture, since Hewett has 

 shown that, out of twenty-three cases of fracture of the 

 frontal bone, in eight there was no evidence whatever of 

 extravasation of blood. (2) Escape of blood. Nor does 

 the escape of blood afford positive proof that a fracture 

 has occurred, for, though in fracture of the anterior fossa, 

 epistaxis may occur, and in injury to the middle fossa, 

 haemorrhage from the external meatus may result, and 

 though blood may find its way into the pharynx from a 

 lesion involving the posterior fossa and passing through 

 the basilar process ; yet, haemorrhage may occur in either 

 of these situations from injury to the superficial struc- 

 tures, such, for instance, as, from the mucous membrane 

 of the nares, or from, in the case of the ear, laceration o'f 

 the meatus itself, or from rupture of the membrana tym- 

 pani, or, lastly, in the case of the pharnyx, from the mu- 

 cous membrane of that cavity, hence escape of blood is 

 only of value when it is persistent and is taken into con- 

 sideration along with other evidences of serious cranial 

 injury. 



