72 THE INTERNAL PAEASITES OF 



moved) , the appearances are commonly such as are here 

 represented from Numan's admirable treatise " Over den 

 veelJcop-blaasivorm der hersenen" 



In Fig. 14, a, we have a single large ccenurus occu- 

 pying the upper and posterior part of the right cerebral 

 hemisphere, whilst in Fig. 15, a, b, c, d } no less than four 

 hydatids are seen projecting from the base of the brain, 

 two in front and two behind, being almost equidistantly 

 separated from one another. The hydatid usually varies 

 in size from a pea to that of a pigeon's egg, but in some 

 instances they are as large as a hen's egg. 



I may remark that the illustrations are reduced to one- 

 half of the natural size ; and in Fig. 14 the letter a refers 

 to a cyst which has been left unopened. When, in the 

 living animal, these parasites gain access to the spinal 

 canal, their form becomes adapted to the peculiarities 

 of their situation ; and thus they have been found to 

 grow to several inches in length. One such example is 

 figured by Numan to the length of ten inches. 



Eeserving my account of the structure, development, 

 and destiny of these bladder worms, I may remark that it 

 is quite a mistake to suppose that coenuri can only reside 

 in the brain. Passing by the question as to whether 

 those found elsewhere may not turn out to be the larvas 

 of several distinct species of tapeworm, I will only 

 observe here that I have myself discovered coenuri in the 

 viscera of an American squirrel, and also in the lungs of 

 a Madagascar lemur. Mr. 0. B. Rose, of Norfolk, 

 was the first to discover them in the flesh of conies, 

 which the warreners not inappropriately termed 

 " bladdery rabbits ;" and M. Baillet has since obtained 

 a coenurus from the pectoral muscle of the same 

 rodent. 



