ON THE OCCURliENCE OF 'WORM-NODULES" 

 IN CATTLE— A SUMMARY. 



By T. HARYEY JOHNSTON, MA., D.Sc, etc., 



Biology Department, University, Brisbane. 



Read before the Royal Society of Queensland, October 28, 1911. 



For the past two years a considerable amount of atten- 

 tion has been paid, both in the Commonwealth and in Europe, 

 to the occurrence of " worm-nests " or " worm-nodules " 

 in cattle in various parts of the world, but more particularly 

 in Australia. Since these nodules are known to be common 

 and widespread in this state (Queensland), which is an 

 important meat-producing country, and since their presence 

 is causing heavy financial losses to pastoralists and meat 

 exporters, I have deemed it advisable to bring together 

 for public information, a summary of what is known regard- 

 ing this parasitic condition. As " worm-nodules " may 

 be produced in man, camels, horses, etc., by allied parasites 

 {Onchocerca, spp.), casual reference is made to them also. 

 The following account refers to that form of Onchocerciasis 

 met with in Australian cattle : — 



llacroscopic appearance : — The naked-eye appearance 

 has been described fully by various authors (Gibson, Park, 

 CI eland and Johnston, Leiper, Gilruth and Sweet), so that only 

 brief mention need be given here. The nodules vary in 

 diameter, from under two to four centimetres in the case 

 of approximately spherical forms, while others of an elon- 

 gate shape may possess a long axis, measuring 7 cms., 

 or even greater. Gilruth and Sweet (1911, p. 7) found one 

 reaching 11 cms. by 8 cms., whilst, very rarely, they meet 

 with others so small that their diameter was only six 

 millimetres. On cutting across a nodule, one notices that 

 the " worm-area " lies at or near the centre, though occa- 

 sionally quite eccentrically. There is very little variation 

 in the size of this area though the thickness of the surround 



