PAEASITES OF ANIMALS. 89 



cles, were visible to the naked eye. On the thirty-eighth day, 

 the eminences appeared more distinctly on the surface, and 

 the heads exhibited signs of their suckers and hooks. 

 Toward the forty-fifth day the Cosnuri were of the size of a 

 bean, and the cavities in which the heads are lodged were 

 formed." Encysted vesicles, containing strayed and aborted 

 worms, were also found in the heart, the diaphragm, and the 

 oesophagTis. Some of the " water-brains" obtained in this ex- 

 periment were given to a dog early in March, and in due time 

 a good crop of the mature tape-worm (^Tcenia coenurus) was 

 obtained by killing the dog, which was done May 24th. These 

 were immersed in white of eggs, in which some of them were 

 kept alive, by changing it daily, for eight days, and sent to 

 several other naturalists residing in other parts of Europe, at 

 Louvain, Copenhagen, and Giessen. Prof. Von Beneden re- 

 ceived his at Louvain, May 27th, and tried the following ex- 

 periments : " On the day of their arrival, at 9 o'clock A. m., 

 half a proglottis was given to each of two young sheep, about 

 two months old, and in the afternoon each of them took an 

 entire proglottis. On the 3d of June, one of them, marked 

 No. 1, swallowed another proglottis. The first symptoms of 

 vertigo made their appearance on the 13th of June ; on the 

 morning of the 15th, I was told that the one marked No. 2 

 was dying. Its head was burning hot, its eyes red, its legs 

 bent under its body ; it beat with its head against the railings, 

 and turned it constantly in one direction. It was then killed. 

 The upper and lower surfaces of the two hemispheres of the 

 brain presented irregular grooves which might be taken for 

 the deserted tubes of certain annelids (Figure 65) ; these have 

 been already mentioned by M. Kiichenmeister. There were 

 about a dozen of them. At the end of these tubes there were 

 the same number of Ooenuri, almost all lodged in the cortical 

 substance of the brain. Some of them were removed with the 

 membranes of the brain. They were of nearly the same size, 

 about three or four millimetres in diameter. These Ooenuri 

 as yet only consisted of a simple milk-white vesicle filled with 

 fluid. The heads were not yet to be seen. * * * 

 * * The second sheep (No 1), was killed on the 

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