DB. BRETT OS THE FLUKE IN SHEEP. 141 



best-lookiug haviug few or noue. Out of thirty-two slicep ex- 

 amined I coudemuetl eighteen, which were ordered by the magis- 

 trates to be destroyed. The parasite always lies in the sarcolemma 

 of the miiseular tibre, longitudinal with it, sometimes straight, 

 sometimes curved. It has the appearance of being alternately 

 segmented, and each segment cellular. I have examined much 

 meat, and I have always found the parasite if fluke is found in the 

 liver ; conse(iuently I associate the two. My opinion is that meat 

 infested with this particular parasite is unfit for human food," Dr. 

 3[ason then adds a sketch of the parasite, and he mounted a specimen, 

 which he has given to me; I have it here for you to inspect pz'csently 

 under the microscope. He obtained the specimen in tliis way. He 

 took a small piece of the meat from the flanlj of the sheep, and with 

 a penknife he cut a very small piece from it in the longitudinal 

 dii'ection of its fibj-es, and then placed it between two glasses, and 

 looked at it with a quarter-of-an-inch object-glass. In appearance 

 it very much resembles the parasite figured by Huxley, and chilled 

 Cenaria ephemera,^" only Mason's parasite is straight or wavy, and 

 Huxley's is curled round in a sac like an ammonite. 



The liver-fluke being called Distoma hepaticmn, I propose pro- 

 visionally to call Dr, Mason's parasite Disloma musculutn. 



Dr. Harley, in a letter to the 'Times' of April 20, 1880, refers 

 to a letter from a " Dartmoor Farmer," who stated that small flukes 

 had been discovered in a lamb only four weeks old. I am told that 

 lambs only begin to eat at two to three weeks old, and it seems 

 strange that the flukes should have been developed in such a short 

 time. It seems probable that they may be developed in more ways 

 than one. f Can it be possible that the ova of flukes can be developed 

 in the muscle of the sheep, and that the parasite I have called 

 Distoma musculum may be a fluke in one of its stages ? 



I fear I have taken up too much time, but before I conclude 

 allow me to make a few practical remarks. 



1st. — It seems possible to produce the rot in sheep at pleasure. 

 " The late Mr. Bakewell was of opinion that after May-day he 

 could communicate the rot at pleasure, by flooding and afterwards 

 stocking his closes, while they were drenched and saturated with 

 moisture."! I am informed that Mr. Bakewell constantly put this 

 into practice, for two reasons. He had a valuable breed of sheep 

 which he did not want to become too common. He therefore 

 allowed some of his sheep which he wished to sell to acquire the 



* Simonds' ' Eot in Sheep,' p. 57. 



t I have been favoiu-ed by our President with the following remarks on this 

 point : — "I qnit« agree with you that flukes may be developed (or, I should prefer 

 saying, introduced into the sheep) in more ways than one. I do not believe that 

 any species of Lvmnaa or pond-snail, much less slugs, which inhabit watery 

 places and are the reputed nurses of the Cercaria or encysted flukes, would be 

 eaten by sheep, because these molluscs live altogether on the ground and not on 

 grass or plants of any kind. It is more prol)able that the embryo of the fluke 

 may find its way into the sheep through the muscles of the sheep's foot or through 

 its skin when it lies down. — /. Gwyn Jeffreys.^' 



X Harrison ' On Eot,' p. 36. 



