PAEASITIC DISEASE OF LUNGS. 367 



the domestic pig, but that it is rare. Alessandrini, on the 

 other hand, says that in Bologna he has found large numbers 

 in the lungs of pigs killed in the public slaughter-houses, and 

 it has since been recognised as frequent in Switzerland and 

 France. The strongylus paradoxus has a narrow mouth, 

 furnished with three papillae ; the caudal bag is bi-lobed, and 

 turned downwards. In the female there is an enlargement 

 where the anus is observed ; the tail is short and pointed. 

 The male is from eight to nine lines in length, and the 

 female about an inch and a half. The females are by far 

 the most numerous of the two. 



Returning now to the parasitic disease of the lungs of 

 sheep, it is clear that there are two distinct stages of the 

 affection, the one mistaken for true tubercular disease, and 

 the other when the worms are fully developed, and lodged 

 in the air passages. Waldinger* was probably the first to 

 give a good account of the latter stage, but the nature of the 

 first was not brought to light until 1840, when La Harpe, of 

 Lausanne, examined the affected lungs, and discovered the 

 ova and young worms in the solid deposit, and recognised 

 them as analogous to the strongylus filaria, met when full 

 grown in the air passages, and sometimes in the act of pierc- 

 ing from the lung tissue through the mucous membrane into 

 the bronchia. [ 



Unaware of La Harpe's discovery, Dr Ercolani, in 1843, 

 when prosector to Professor Alessandrini in the University 

 of Bologna, was struck with the appearance presented by 



* Abpaulung aberd Wurmer und Lungen a Staape. Wien, 1818 

 t I do not agree with Dr Crisp's theory of the germs of the parasite 

 being carried back from the stomach to the mouth in the act of rumi- 

 nation, and then finding their way into the trachea. As with the 

 germs of the cysticerci only the young animals are affected, because 

 they cannot pierce the tissues of older ones. 



