HYDATIDS IN THE BONES. 171 



commencement, although in some cases the patient 

 may complain of a fixed, deep-seated sensation of 

 uneasiness at an early period of the affection. A 

 smooth, uniform tumour, of a bony consistence, makes 

 its appearance at the diseased part ; it increases 

 gradually and regularly in size ; it subsequently 

 becomes soft at various points, and fluctuation, toge- 

 ther with a hard, osseous border around the softened 

 portion, may sometimes be felt. If the tumour be 

 deeply situated, and surrounded by a dense covering 

 of muscles, it may remain undiscovered for a con- 

 siderable length of time ; and the bone becomes so 

 thinned and brittle, in consequence of the gradual 

 absorption, that, during a muscular effort, it is 

 suddenly broken. 



When the cyst is opened, either spontaneously, or 

 by a bistoury, or by any other means, the hydatids 

 are liberated, and inflammation and suppuration are 

 produced. General comphcations, which are usually 

 of a serious nature, then supervene ; the suppuration 

 lasts for a long period, because the rigidity of the 

 bony tissue prevents the contraction of the cyst ; 

 and the constitution of the patient is thus gradually 

 undermined, so that the case often terminates fatally. 



