THE LUNG THREAD-WORM. 223 



was filled with them, and a number of them are now preserved 

 in the museum of the Smithsonian Institute at Washington. The 

 author found them (along with numerous specimens of atrongylus 

 filaria, in the lungs), in the flock of South- 

 downs belonging to Royal Phelps, Esq., of 

 Babylon, L. I., and also in his own Cotswold, 

 Leicester, and native sheep, which had been 

 allowed to pasture occasionally along the banks 

 of a stream, and to drink for a whole summer 

 at a running spring in which many watercresses 

 and other aquatic plants grew. In these cases 

 the medicine above prescribed brought about 

 an entire cure. 



As the course of the disease is rapidly ex- 

 haustive, sheep that are affected should be well 

 fed with nutritious and easily digested food ; 

 Fig. 82. FLUKE a pint per dav ^ for each gheep^ o f Hnseed-oil- 



5EB ' cake-meal mixed with bran, will be of the 

 greatest service on their recovery, or as soon as the appetite returns. 

 The Lung Strangle. The "lung thread-worm," (strongylus 

 filaria], lives in the wind-pipe, the bronchial tubes, and the tissues 

 of the sheep's lungs. It is a white, thread-like worm, from one 

 inch to three inches in length. Its natural history is supposed to 

 be as follows. The worms present in the lungs breed and produce 

 eggs, which contain fully developed young, wound up in a spiral 

 form in a thin shell. These embryos soon leave the shell and 

 move about in the tubes, causing great irritation and a secretion of 

 mucus, upon which they feed and grow. It is not certainly known 

 as yet if the sheep in the violent coughing caused by the irritation 

 expels any of the eggs or young worms, and that they then pass a 

 portion of their existence in the open air, finding their way into 

 the lungs of fresh bearers by the trachea in the passage of the 

 food through the mouth or gullet, or from the stomach in the act 

 of rumination ; or if the worm completes its whole existence in 

 the lungs of its bearer. It is most probable that the former sup- 

 position is the true one, as it explains the fact that the worms are 

 often found in young lambs in such quantities as to cause suffoca- 

 tion. Besides, it is known that flocks which follow other sheep 

 upon pastures, or which feed upon fields that have been manured 

 with sheeps' dung, have been attacked with this disease. An in- 

 teresting case in point is stated by a Pennsylvania correspondent 

 of the Country Gentleman of March 25th, 1875. Some ram lambs 

 were pastured in a field upon which their dams had been kept the 



