136 Descriptions of Preparations. 



organs and that of those of animal life, ibid., p. 549, and 

 Art. ' Zeugung' in Wagner-'s Handworterbuch fiir Physiologie, 

 Bd. iv., pp. 7 19-1 S53. 



43. Many-headed Bladder-worm 



{Caenurus Cuniculi), 



In its cystic stage, from the region of the masseter muscle of a rabbit 

 {Lepus Cunicalus). 



This specimen illustrates the cystic stage in the metamorphoses 

 of the true Taeniadae. It belongs probably to the same species 

 as the one individuals from which are, when in the cystic stage, 

 lodged usually in the brain of the sheep, and are the cause of the 

 disease commonly known as the 'sturdy/ 'gid/ 'staggers/ or 'turn- 

 sick.^ The specimen consists of a white walled semi-transparent 

 sac; and a larg-e part of its walls having been removed, one end of 

 it is seen to be beset on its interior surface with a number of closely 

 apposed but distinct opaque white bud-like bodies, the area occupied 

 by which is prolonged out laterally into lobes indicating the conti- 

 nuing proliferation of the cyst. Two smaller cysts, one of which 

 is similarly bestudded internally, are attached by mere filaments 

 of tissue to the lower parts of the large cyst, to the proliferation 

 of which they may also be considered to be due. For, though it 

 is possible to suppose that these all but perfectly isolated out- 

 growths may have been produced by the pinching off from the 

 mother vesicle of small portions of its walls, the large cyst having 

 been necessarily subjected to much pressure from time to time 

 by the masseter muscle ; cysts of this tapeworm showing a ten- 

 dency to form or forming similar accessory vesicles, have been 

 figured from parts such as the brain, or lungs and liver, where 

 no constriction could be effected by muscular pressure ; and the 

 analogy of certain of the forms of the proliferating cysts of the 

 Taenia Echinococcus would appear to indicate that the formation 

 of such pedunculate outgrowths is one of the normal modes of 

 self- multiplication in the cystic stage of the Taenioid metamor- 

 phoses. The white gemmules represent the ' heads,' or ' nurses^ 



