230 THE GROUSE IN HEALTH AND IN DISEASE 



On June 19th, 1909, the culture which had just undergone metamorphosis, 

 and which was therefore in the active migrating stage, was administered 

 to an adult male bird one year old. The droppings of this bird were entirely- 

 free from Trichostrongylus ova when the experiment was begun. An examination 

 of the ffeces on the successive days showed that no infection had taken place. 

 By June 26th the culture had undergone further development changes, and 

 showed a large number of encysted forms. A dose was again administered by 

 Dr Wilson, 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 adminis- 

 tered. 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 j^ost-mortem examination I came to the conclusion that 

 the bird had been killed by the passage of some of the last culture into the 

 lungs, for there was considerable 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 Trichostrongylosis by the administration of encysted 

 metamorphosed Trichostrongylus jfer-gracilis larvae. It served to establish, 

 however, that these larvte can reach the casca 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 cfeca 

 by a large number of Ti-iehostrotigylns jyergracilis produced such a marked 

 eff'ect upon the mucous membrane as to fill the cpeca with blood. 



In the second experiment made by Dr Wilson ray 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 llf ounces. The ctecal droppings were as full of 

 Trichostrongylus pergracilis ova as those of a bird suffering from Tricho- 

 strongylosis, and the bird itself showed a similar condition of progressive weak- 

 ness and emaciation. The mucous membrane of the caeca was covered wdth 

 Trichostrongylus pergracilis, but no evidence of extravasation of blood into 

 the lumen of the caeca was found on the death of the bird. Apparently 

 that seen in the first case must have been associated in some way with the 

 development of the parasite before reaching maturity. 



These two experiments indicated in so far as such a limited number may, 



