HYDATIDS. 



153 



exhibits vibratory or contractile movements. This 

 membranous cyst may be regarded as the body of 

 the animal, and it is studded thickly but irregularly 

 with numerous heads, or rather perhaps slightly 

 elevated mouths, each being margined around with 

 minute arms, and being also furnished with suckers, 



COMMON HYDATID. A. MAGNIFIED HEAD, B. 



calculated for attaching the mouths to the tissues of 

 the part in which they are seated, and from which 

 they imbibe their nourishment. 



