156 HYDATIBS. 



brain, hundreds of them may be forced through the 

 numerous heads of the hydatid by the slightest 

 pressure ; and at other times, when the cyst is 

 examined, numbers of them will be found in or 

 protruding from its various oval apertures." 



Another curious fact may here be noticed. One 

 of these hydatids is very often found to have its 

 cyst filled with multitudes of perfect but small 

 hydatids, of various sizes, to the amount of scores. 

 Instances of this kind have frequently been ob- 

 served ; and Mr. Youatt gives one in which a hyda- 

 tid larger than the egg of a goose, found in the 

 abdominal cavity of a monkey, contained more 

 than ten thousand minute but perfect cysts, toge- 

 ther with a countless number of granules, which 

 lined the membranous cyst of the parent hydatid, 

 and which may be regarded as the germs of a 

 future race. 



Here, then, three questions present themselves : 

 First, is it from these minute multitudinous granules 

 that the worms in question spring ? Secondly, are 

 these worms hydatids in a larva or imperfect state ? 

 or, thirdly, are they themselves parasites of a para- 

 site, and, in fact, not the germs or larvae of hy- 

 datids ? We have not the means of positively 

 answering these queries. They involve difficulties 

 which future naturalists may perhaps be enabled to 

 clear up. The constancy, however, of the presence 

 of the worms, and their numbers, in the turbid fluid, 

 when the granules are either less numerous than 



