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IX. — Report on the Parasitic Lung Disease of Lambs. By 

 Professor J. B. SiMONDS, Principal of the Royal Veterinary 

 College. 



Since the issuing of the list of questions to the members of the 

 Lincolnshire Agricultural Society, on the subject of the lung- 

 worm disease of lamljs — a copy of which is attached hereto — 

 various experiments have been had recourse to for the purpose 

 of throwing further light on the development of the worm or 

 rather worms which are the cause of the malady. 



These experiments cannot be said, however, to have been very 

 successful, and it is not improbable that even years may pass 

 without much additional knowledge being obtained on so 

 intricate a subject as the successive stages of development of 

 these and other nematoid parasites, when located within or 

 when external to the organism of animals. Although this is so, 

 still knowledge of this kind should be continually sought for, 

 as it lies at the foundation of the means to be adopted to limit 

 the extension of parasitic diseases, and also of those means on 

 which their cure chiefly depends. 



It is now satisfactorily ascertained that more than one variety 

 of thread-worm finds its way into, and inhabits for a time, 

 the air passages of sheep and lambs. Attention was called to 

 this circumstance several years ago by Continental investigators, 

 and from time to time specimens of both worms have been 

 seen by British helminthologists. Referring to this subject 

 Dr. Cobbold — the Professor in the Royal Veterinary College, 

 on whom the investigation of parasitic diseases devolves, — says 

 that " the well-known lamb disease, though generally supposed 

 to be due to the presence of a single species of worm, called 

 the common lung-strongle, or Strongylus filaria, is in reality 

 due to the occurrence of at least two different parasites belonging 

 to the same group." 



" For years past it has been known to Continental helmintho- 

 logists that a second species of nematode worm is usually 

 associated with the above-named parasite, the form in question 

 having been originally described by Professor Leuckart, under 

 the title of Strongylus rufescens.^'' 



" I am the more desirous," he adds, " of calling attention to 

 this fact, since Dr. Crisp, an earnest worker in the cause of 

 parasitology, believes that he has discovered a new worm in 

 the lungs of lambs and sheep, which he calls a Gordiusr " I 

 entertain no doubt that Dr. Crisp's gordian worm is the adult 

 representative of the immature worm found by Professor Brown, 

 some years ago ; fresh specimens having also recently been 



