234 THE GROUSE IN HEALTH AND IN DISEASE 



one year old. The droppings of this bird were entirely free from 

 Trichostrongylus ova when the experiment was begun, and there- 

 fore the bird was entirely free from all suspicion of prior infection. 

 An examination of the faeces on the successive days showed that 

 no infection had taken place. By June 26th the culture had 

 undergone further developmental changes, and showed a large 

 number of "encysted" forms. A dose was again administered 

 and some four days later ova of Trichostrongylus pergracilis 

 were found in the droppings. The number of ova increased 

 on successive days. On July 3rd a further dose of the same 

 culture, now thirty days old, was administered. The bird died 

 five days later, showing distinct loss in weight, the presence 

 of a large quantity of chalky fluid in the rectum, and the caecal 

 contents red with blood. From the post-mortem examination 

 the conclusion was formed that the bird had been killed by the 

 passage of some of the last culture into the lungs, for there 

 were obvious signs of pneumonia, and quantities of the culture 

 were found in the fine tubules. 



This first experiment was therefore not wholly conclusive 

 as regards the actual induction of Strongylosis by the 

 administration of encysted metamorphosed Trichostrongylus 

 pergracilis larvae. It served to establish, however, that these 

 larvae can reach the caeca of the Grouse, attain their adult 

 condition, and become sexually productive in the very short 

 space of four days. It also demonstrated that the sudden 

 invasion of the caeca by a large number of Trichostrongylus 

 pergracilis produced so marked an effect upon the mucous 

 membrane as to fill the caeca with blood. 



In the second experiment the culture was much older, 

 and contained encysted forms. The doses were repeated 

 periodically, with the result that in the course of two and a 

 half months the bird fell in weight from 17 ounces to 11 J ounces. 

 The caecal droppings were as full of Trichostrongylus pergracilis 

 ova as those of a bird suffering from Strongylosis, and the 

 bird itself showed a similar condition of progressive weakness 

 and emaciation. The mucous membrane of the caeca was 



