WORM NODULES IN CATTLE IN N.S.W. 
The Distribution in New South Wales of Worm 
Nodules in Cattle due to Onchocerca gibsoni. 
By J. Burton Cleland, M.D., 
; and 
Bessie M. Somerville, B.Sc. 
In Bulletin No. 2, entitled “ Worm Nodules in Cattle,” the Institute of Science 
and Industry published some results, obtained by Dairy Inspectors, showing the 
geographical distribution in New South Wales of worm nodules due to Onchocerce 
gibsoni (Jnstn. and.Cld.). It has been felt that these returns were not sufliciently 
extensive, and that a systematic examination by one or two individuals might 
reveal more clearly the relative prevalence of these worm nodules in different parts 
of the State. With this object in view, Miss Somerville was appointed by the 
Advisory Council to supplement the examinations already made, or then being 
made, by one (J.B.C.) of the sub-Committee on Worm Nodules in Cattle. 
Tenterfield 
2B 55% 
Glenianes 
betta 
g ON jonrigosre % 
Bettis amides 
syrah 
arora 
cia 
OMudgee 
1300 orem, 
Orangesze 
eae Ssipgatnurst 
2040 AES operon 
‘Moo 
taut AST W503 < bur 
Denil Pcie chieea ex ‘ = ee 
PLS Sher bless “7 NEW SOUTH WALES 
; SHOWING THE DISTRIBUTION OF 
WORM NODULES IN CA 
ScALe OF MILER 
Ter eee 
Percentage of cattle atfected », y, shown 15% 
Mi ludes of lacalives, in tet, above sea leve/, GIT 
mune _)}) 
The accompanying report is the result of the examinations thus made, and may 
have a very important bearing in elucidating the life history of the worm in 
question. 
This survey was begun with the intention of ascertaining in what parts of the 
State local cattle do not develop worm nodules; in what parts they occasionally do 
so; and in what places the nodules are common, or even extremely abundant. It 
was thought that if reliable information could be obtained from a great portion of 
this State, some light might be thrown on the means by which the larvee are con- 
yeyed from one bovine to another. Obviously if in some places local cattle never 
develop worm nodules, in spite of the introduction into the herds to which they 
belong of cattle with worm nests from other districts, then the means of trans- 
mission must, for some reason, be defective in the district in question. If, on 
the other hand, locally-developed nodules ‘are few, one may infer that the trans- 
mitting vector is present but not common, or that some other factor renders 
transmission difficult. Again, where local nodules are common, the vectors are 
179 
