i88 SOME MINUTE ANIMAL PARASITES 



peasants, pastured largely on bogland, show no 

 sign of disease. 



From the foregoing remarks it is obvious that no 

 general statement can be made regarding preventive 

 measures, since no two places are under the same 

 biological and climatic conditions. Hand-picking 

 of ticks, liming of pastures, together with observance 

 of quarantine conditions, are certainly efficacious 

 in small outbreaks, and the use of various arsenical 

 dips and sprays, paraffin and petrol washes and other 

 preparations undoubtedly is of much assistance. 

 When large areas are affected, the carrier must be 

 ascertained and its biology most carefully studied. 



The life-history of every parasite contains a 

 vulnerable spot, and a systematic attack on the 

 organism must be made at this period if it is to be 

 of effect. There is little doubt that in the case of 

 the carriers of redwater the weakest period is the 

 larval stage, and it is for the destruction of the 

 larvae that the greatest efforts need to be made. It 

 is also true that cattle and sheep will die from 

 "tick-worry " without necessarily incurring redwater. 

 Though this is a small occurrence in comparison 

 with what follows redwater, yet it is sufficiently im- 

 portant to justify an " anti-tick " crusade. 



Finally, a word of warning is needed with regard 

 to the possibilities of the carriage of disease to 

 hitherto immune countries. It is not sufficient that 

 cattle exported alive from infected areas are free 

 from disease and from ticks. Any hay, straw, and 

 corn from such places need the strictest possible 

 examination, for larval ticks have been found on the 



