196 



STRONG YLUS OVIS-PULMONALIS, Diesing. 



Plate XXXI. 



Left liiDg diseased by Strongylus aiHS-pulmonalis, the hair lung-vronu. Natural 

 size. Each dot is caused by the irritatiou set up by a young worm, aud its size cor- 

 responds to Ihe age of the worm. The larger patches consist at first of separate 

 dots ; as these enlarge they run together and finally become so fused that their 

 identity is lost. The patches show the stage at which the worms become adult and 

 produce their young, which wander into the adjacent air cavities. 



