The Sheep-Fluke. 11 



Burning. 



Burning off grazing laud has become a well-recognised method of 

 "cleauing" it. The reason for the operatiou is very simple, aud it is 

 this : Any small organisms clinging to the herbage, such as the eggs and 

 larvffi of parasites, will be killed by the fire. While this supposition is in 

 the main true, it is well to know whether, and in what way, burning may 

 fail to "clean" the land. So far as fluke is concerned, we have to consider 

 the chances the eggs and larval stages have of escaping the conflagration, 

 and it may be said at once that the chances are by no means few. Most of 

 the eggs that exist in green dung will be left 

 unharmed. Though the surface of the pellets 

 may be scorched, the heat will not penetrate 

 them sufficiently to kill all the fluke eggs they 

 may contain. Moreover, all the excrement 

 lying on bare paths will remain unscorched. 

 Again such excrement as lies in damp places or 

 among incombustible material such as green 

 grass will also escape the fire. When we recol- 

 ect that it is only from comparatively fresh 

 dung lying in or near water, or at least where 

 it will sooner or later be moved into water, ^'^"fou^cf^^ °sheepdung,''^and 

 that fluke may be expected to develop, we shall seen with the microscope. 



be easily convinced that fire is by no means so 



cleansing as Australian sheep-owners are wont to believe. The fire cleanses, 

 to a certain extent, so far as it goes ; the difficulty is that tJie places where 

 it won't go are the very places most requiring to he cleansed. 



Pire should be applied and controlled, not left to accident and allowed to 

 take its own wild course. The sheep-owner who is able, during a time of 

 drought, to burn of£ his low-lying and swampy places will reap the greatest 

 benefit, and such a course can occasionally be adopted by those who plan for 

 it a sufficient time in advance. Even when most successfully carried out, 

 however, there can be no hope that the fluke will be eradicated. Some, 

 possibly many, eggs, cysts, and snails will be killed ; but it is equally true 

 that some will remain to multiply and infest the stock as before. 



We must conclude, therefore, that while fire may be made under favour^ 

 able conditions to ameliorate the fluke trouble for a few months, it cannot 

 be relied upon alone to successfully combat the disease, and that only when 

 utilised in time of dryness and drought, and in conjunction with other 

 measures, is it very effective. 



It must not be forgotten that drought alone is sufficient to inflict great 

 injury upon the eggs and larvae of the fluke, and that this is the reason that 

 sheep often do remarkably well for a season or two afterwards, so well 

 indeed as to have given rise to the opinion among sheep-owners that a drought 

 is not an unmitigated evil. 



When burning off for fluke the wise pastoralist will not forget to take 

 into account the effect of the fire upon his pasturage. Fire destroys seeds, 

 which may be useful or baneful, according as they are those of good forage 

 plants or of noxious weeds. 



Overstocking. 



This is a widely prevalent evil, which results, among other things, in 

 increasing the abundance of fluke. It is very easy to see the reason for 

 this. Overstocked land becomes close fed, so that stock have to nibble very 



