CHAPTER X 



" GROUSE DISEASE " — CONTINUED — STRONGYLOSIS * 



Part I. — The Threadworms {Nematoda) ~ 

 By Dr A. E. Shipley 



Part II.- — On the Development and Bionomics of Teichostrongylus 



PERGRACILIS 



By Dr Robert T. Leiper 



(I.) Family Strongylidae 



(i.) Trichostrongylus pergracilis (Cobbold) 



Synouym : Strongylus gracilis Cobbold 



This round-worm was first described under the name of Strongylus pergracilis 



(Cobbold), by Cobbold,^ whose words we quote : — 



" Characters. — Body filiform, finely striated, gradually diminishing 



in front, uniform in thickness below ; head bluntly pointed, with a simple oral 



aperture ; tail of the male furnished with a bilobed bursa, each half supporting four 



pointed rays ; spicules two, thick, and slightly divergent ; tail of the female 



slightly swollen above the subterminal anal orifice, rather sharply pointed at the 



tip ; vaginal opening situated at the upper part of the inferior sixth of the 

 body. 



" Length of male \ inch to f inch ; body ^^ inch in diameter, tapering 



anteriorly to ^^Vir ^^^^ at the head ; greatest breadth immediately above the bursa 



TTjr inch. 



^ The term " Strongj'losis " is employed in this chapter to denote the disease caused by Tricho- 

 strongylus 'pergracilis (Cobbold) ; though it would perhaps be more strictly correct to name the disease 

 Trichostrongylosis. 



- Reprinted with slight alterations from the Proceedings of the Zoological Society of London, 1909. 



3 Cobbold " Grouse Disease," p. 16. 



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