ANIMALS WHICH LIVE ON OR WITHIN GROUSE 201 



alive, owing to its transparency. On shaking up some of the contents 

 of the caecum in 75 per cent, alcohol to which has been added a few 

 drops of corrosive sublimate and acetic acid, the worms become opaque 

 and more visible, and they can be easily seen by compressing between 

 two microscope slides a drop or two of the caecal contents and holding 

 them up to the light. The worms, if there be any present, then appear 

 as thin, white transparent lines. The males are some 8 mm. in length, 

 the females 10 mm. 



No one has ever seen, and probably no one will ever see, this 

 strongyle enter the body of a Grouse ; but that it does so in the larval 

 form, and that directly, i.e., without the intervention of an intermediate 

 host, seems clear. When swallowed the larvae make their way along 

 the alimentary tract and turn up into the caeca, where they rapidly 

 develop into adults. 



The serious injuries caused by the presence of T. pergracilis in the 

 caeca, the accompanying symptoms, and the general pathology are 

 described in chap. viii. To distinguish the disease from others which 

 afflict the Grouse, it may be called Strongylosis. 



(ii.) Fam. STRONGYLID.E. 



XIII. Syngamus trachealis (Von Sieb). 



(The Red or Forked Worm.) 



This common pest of the fowl-yard and pheasant-coop has been found 

 but three times in the Grouse. Probably the free and unconfined life 

 of the bird, together with the comparative paucity of earthworms in the 

 moors, protects Grouse from " gapes," as the disease caused by the 

 forked worm is called. There seems no reason at present to incriminate 

 this worm of causing any trouble to Grouse. One of the cases observed 

 was a young bird from Argyllshire. 



(iii.) Fam. TRICHOSOMIDJS. 



This family includes two human parasites, the whipworm of man 

 and the worm which lives in the human intestines, and as larvae 

 migrate to the muscles, causing the painful and ofttimes fatal disease 

 of Trichinosis in man, pigs, and rats. The genus Trichosoma occurs 

 in all classes of vertebrates, especially in mammals and birds. It 

 includes some seventy different species. 



XIV. Trichosoma longicolle (Rud.). 

 (The Whipworm of the Grouse.) 



This round worm is far less common than the Strongyle. It occurs, 

 in fact, sparingly, sometimes alone, sometimes associated with the 

 transparent tapeworm, but always in the duodenum. The male 



