80 TREPANNINO FOE CCENUEUS. 



T&nia serrata. Beyond this, the cysts of these Ccenuri were of 

 extraordinary dimensions, since they would have exceeded the 

 size of hens' eggs if, when in a fresh condition, they had been 

 filled with water. They, moreover, contained a remarkable 

 number of scolex gemmae, which covered the interior surface of 

 the cyst in masses thickly pressed together. Very many of the 

 already developed scolices were everted, so as to project con- 

 siderably on the exterior surface of the parent cyst, a pheno- 

 menon which I have seldom observed in those of sheep. 



Although the fact has been proved, that the disease of the 

 staggers, arising from the presence of Ccenurus cerebralis, can 

 be cured by trepanning, still sheep-owners must not always 

 reckon upon the absolute success of the operation, since, as has 

 been already stated, the result must depend upon the situation 

 of the parasite ; and as it is impossible to know if two, or even 

 several cysts, may not have established themselves at the same 

 time in the nervous centres of the affected animal, of which one 

 alone could be removed by trepanning, and that the cyst which 

 lay nearest to the surface. Furthermore, even though the 

 animals can be cured by the removal of these parasites, the 

 question arises, if such animals, the vital powers of whose brain 

 have been disturbed by the presence of this cyst, can be said to 

 be cured in the full meaning of the word? Do the diseased 

 changes which a considerable- sized Ccenurus-cjst engenders, 

 through displacement, pressure, and wasting away of the sub- 

 stance of the brain, become so entirely removed after the extrac- 

 tion of the worm, that the vital powers of the brain can be again 

 restored in their full integrity ? Will there not still remain 

 traces of changes engendered by the disease in such a brain, 

 which although causing no striking interruption of the animaPs 

 nervous energies, may yet more or less affect its strength, dura- 

 tion of life, and fruitfulness, and render it inferior to a thoroughly 

 healthy individual of the same race. 



From what has been stated, it follows that the cure of the 

 staggers, when it has once broken out, is always a difficult, and 

 very often an impossible task ; hence it would be much more 

 worth while to take precautions for preventing it. The only 

 rational prophylactic treatment must consist in employing such 

 means as may prevent the immigration of the young of that tape- 

 worm from which the Coenuri are developed. As, according to my 

 experiments, the Ccenurus cerebralis changes, in the digestive canal 



