APPENDIX F 101 



Further cultures were made also of the Trichostronglyus larvae L arva i 

 hatched from the ova passed in the csecal excreta of infected birds. cultures - 



No difficulty was experienced in obtaining these. The csecal dejecta full 

 of ova, having been placed in water, produced a very large number of larval 

 worms actively moving in the water within a day or two. But the difficulty 

 was to keep these larval worms alive and growing for a sufficient length of 

 time to enable them to undergo their proper metamorphosis. 



It was at this point in the inquiry that Dr Leiper was called in to assist 

 the Committee with his special knowledge of Helminthes. 



Cultures of early Trichostrongylus larvae had already been administered 

 to birds in which there were no nematodes, but without any result ; 



Failure of 



and the reason of this was soon discovered by Dr Leiper, who showed earlier ex- 

 periments. 



that up to a certain stage in its metamorphosis the larval Tricho- 

 strongylus could be swallowed in any numbers by a Grouse without any ill 

 effect. The proper metamorphosis occurred a variable number of 

 days (sometimes eight and sometimes as many as seventeen days) phosisof 

 after hatching from the egg, and until this metamorphosis had taken 

 place the larval Trichostrongylus would be simply digested or passed through 

 the intestine of the Grouse. 



This metamorphosis is described fully by Dr Leiper, who gives a complete 

 account of the development and life history of the Trichostrongylus pergracilis, 1 

 while its anatomy has been described by Dr A. E. Shipley. 2 



It remains here to explain how the experiments were carried on at 

 Frimley, by which these views were confirmed, and by which the 



theory of "Grouse Disease" held by the Committee was shown to tion of ex- 

 periments. 



be the true one. 



The first unsuccessful experiments were made on three young Grouse, ( M) ( P) 

 and (S) of the year, i.e., of about four months old. Early ex- 



(M) Weight 15^ OZS. periments. 



(/>)_ Weight 16 i 

 (S) Weight 16 



Oct. 9th. The droppings of these three birds were carefully examined and 

 were all found to be wholly free from Trichostrongylus and from other nematodes 

 and from cestode worms, so far as could be ascertained by examination of the 

 droppings, which in an infected bird almost invariably carry the ova of these worms. 



1 Vide vol. i. chap. x. p. 224. 2 Vide vol. i. chap. x. p. 207. 



