174 THE GROUSE IN HEALTH AND IN DISEASE 



inflammation of the duodenum and smaller intestine, Coccidia 

 have been the cause and have been overlooked, and that the 

 more obvious threadworms (Trichosoma) have really little or 

 nothing to do with the engorgement. 



It may exonerate the tapeworms Hymenolepis and Davainea 

 to some extent, that both may be present in masses without 

 any accompanying inflammation, but the association of a large 

 number of the threadworm Trichosoma in the duodenum with 

 the symptoms referred to is too frequent to allow this nematode 

 to escape blameless. Trichosoma is probably a harmful worm, 

 but as it only occurs occasionally, the damage done by it is 

 comparatively trifling. 



Typically the duodenum when badly infested by Hymeno- 

 lepis looks bulky and translucent, swollen and soft, and is of 

 a pinkish yellow colour, with thin walls. The upper end of 

 the ascending limb is often deeply stained by contact with 

 the liver. The fluid contents, always small in amount, are 

 generally yellowish, and may be blood-stained if Hymenolepis 

 and Trichosoma are present in excessive numbers. 



It is not a rare thing to find that in a sick bird the control 

 of the lower sphincter of the gizzard is lost at the point of death 

 or somewhat earlier, and that the grits have passed out of 

 the organ in large quantities into the duodenum. Normally 

 the grits are retained in the gizzard for a considerable time, 

 certainly for months, if they are of any size. Much depends 

 upon the nature of the food, and, as already explained, the 

 presence of hard, woody seeds may lead to the loss of most 

 of the gizzard grits, in which case they are passed with the 

 dejecta. 1 



Passing now to a consideration of the small intestine, and 

 its pathological manifestations, the first noticeable point is its 

 external appearance when really full of the large tape- 

 worm Davainea urogalli, as is so frequently the case ; the 

 gut is distended, and appears fatty, thin-skinned, whitish - 

 yellow in colour, and rather translucent. Within, there are 



1 Vide p. 112. 



