NEW EISTTOZOON FEOM THE OSTRICH. 187 



From experiences long ago gathered bj^ myself in the investigation of 

 Grouse and Pigeon epidemics, respectively, and from what I have also 

 discovered to obtain in the case of certain animal epidemics not hitherto 

 judged to be of parasitic origin, I was in no way surprised at this announce- 

 ment of a new avian epizooty due to parasitism. All the helminthic out- 

 breaks present certain features in common. As fatal epidemics or plagues 

 they come and go ; and although the parasites that cause them are never 

 really altogether absent, the evil results of invasion are only manifested 

 and recorded when the parasites are sufficiently numerous to make their 

 presence felt — that is, epidemiologically speaking. All epizootics of this 

 character are immediately due to excessive multiplication of worms, the 

 unusual prevalence being itself due to exceptionally favourable conditions. 



When the Grouse-disease prevailed, alarmists predicted that these 

 valuable game-birds ivould soon share the fate of the Dodo ; yet, as I 

 pointed out at the time, this conclusion was based upon an entire mis- 

 understanding as to the nature of the disorder. If it could not be shown 

 that the Grouse epidemics of former years were due to parasitism, I at 

 least demonstrated that the outbreak of 18/2-73 was principally caused 

 by a Nematode not then known to science. This worm I named Strongylus 

 pergracilis *. Upwards of thirty Grouse were examined by me during the 

 epidemic, most of the diseased birds having been either captured alive or 

 shot on the Earl of Cawdor's moors. The Grouse and Ostrich Strongyles 

 bear a considerable resemblance to one another ; but the Grouse worms are 

 much longer and otherwise differ. Not improbably the mode of develop- 

 ment is similar, both requiring a change of hosts. Be that as it may, and 

 in absence of special researches upon this point, I may observe that the 

 method of dealing with the Ostrich epidemic was in the right direction. 

 Had the salines been combined with lime-water, I think the treatment 

 would have proved more or less effective. What is really wanted is some 

 drug that is known to exert a special action on Nematode worms without 

 injuriously affecting the host. It seems to me that the so-called milk of 

 Papaw (Carica papaya) is likely to answer the purpose. The remark- 

 able properties of the active principle of this drug (as made known by 

 M. Wurtz, and referred to at a former Meeting of this Society) would at 

 once suggest the use of Papaw in any form of uematelminthiasis ; and 

 the practical efficiency of the drug as an oxyurifuge has been attested by 

 Dr. Peckolt t- Several years ago Dr. Marcet showed that the perivisceral 

 fluid of the larger Nematodes closely corresponded with the ordinary juice 

 of flesh ; and without doubt this fluid is mainly concerned in sustaining the 

 life of the worms t. Since, therefore, Pajjaine possesses the power of 



* ' The Grouse Disease ; a statement of facts tending to prove the parasitic 

 origin of the epidemic' ' The Field ' Office, Loudon, 1873. 



t Pharmaceutical Journal, vol. x. Sec also Mr. Clu-isty's ' New Comniercial 

 Plants and Drugs,' No. iv. p. 38 : Loudon, 1881. 



I Proceedings of the Royal Society, vol. xiv. p. 69 (ISGl). 



