164 BULLETIN 16 2, UNITED STATES NATIONAL MUSEUM 



pharynx the life cycle of this nematode worm involves a secondary 

 host, which Doctor Cram has discovered to be a grasshopper. 



" The intestinal worm Ascaridia lineata is the commonest of all the 

 internal parasites and in certain sections of the range of the ruffed 

 grouse as many as 75 per cent of the birds examined were found to 

 be infected. This worm is comparatively large, ranging from 2 to 4 

 inches in length. It is yellowish white and pointed at both ends. 

 Because of its size and abundance it is reported by sportsmen more 

 frequently than all other parasites combined. Ascarids normally 

 reside in the intestine and while there do comparatively little harm 

 aside from absorbing a certain quantity of food. A number of 

 cases have been found, however, where the worms have been outside 

 the intestine among the vital organs and in the body cavity where 

 there was no evidence of shot wounds or scars to indicate that the 

 worms had made their way through artificial openings. 



"The hatching of the eggs occurs normally after the eggs are 

 swallowed, and the life cycle does not involve a secondary host. In 

 the larval stages this parasite is capable of doing serious injury to 

 the mucous lining of the alimentary tract, especially in young birds. 

 Some of the larvae may even penetrate the mucous lining and thus 

 be transported by the blood stream to other parts of the body. 

 Furthermore, wounds made by the larvae may open the way to 

 infections of a serious nature. 



" The cecal worm Heterakis gallinae is a small nematode parasite 

 usually found in the ceca. Rarely it occurs in the small intestine, 

 colon, and rectum. It is white and very rigid, and the head is bent 

 dorsally, a character that serves to distinguish it from young Asca- 

 ridia. The eggs of Heterakis pass in the feces and under favorable 

 conditions of temperature and moisture develop in about 10 days to 

 the point where the eggs contain infective embryos. When the eggs 

 are swallowed by the grouse the embryos are released and then de- 

 velop into adult worms in the region of the ceca. This parasite is 

 known to have an important relation to the dreaded disease entero- 

 hepatitis commonly known among poultrymen and game breeders as 

 blackhead. The eggs of Heterakis may carry for great lengths of 

 time the blackhead germs and thus facilitate the spread of this di- 

 sease from bird to bird. A species of Contracaecunv has been taken 

 from the ruffed grouse. 



" Tapeworms, designated also as cestodes, constitute important 

 parasites in the intestines of certain groups of birds. Three species 

 of minor importance have thus far been found in the ruffed grouse. 

 "A large number of the ruffed grouse examined have been found 

 to be infected with flagellate protozoan parasites. Thus far six- 

 species have been identified, of which Histomona<$ meleagridi* 



