10 The Sheep'FluJce, 



A single snail of this species will often harbour several hundred of the 

 redia or cercaria, as the two intermediate forms of the fluke are respectively 

 termed, a fact Avhich is in accord with those recorded in case of the corres- 

 ponding European snail. 



Such, in brief, is the story of the discovery of the Australian intermediate 

 host of the sheep fluke, a narrative which, in its proper place in these pages, 

 will be again adverted to and enlarged upon. By this discovery, the sus- 

 picions of European naturalists that the Australian intermediate host might 

 prove to be another species of snail than that which serves in Europe were 

 confirmed, and the doubts as to whether there was in Australia any inter- 

 mediate host were cleared up. 



It may be permitted us to doubt, however, whether this discovery, satis- 

 factory as it undoubtedly is, goes far enough to warrant us in saying the 

 life-history of the Australian sheep-fluke is essentially identical with that of 

 the European form. There are still many points upon which evidence is 

 wanting before such a statement will have the full warrant of science. 



At this point it will be well to state that redia and cercaria are common 

 in a wide variety of molluscs, there being probably no less than a hundred 

 different species of such intermediate forms already known, many offering a 

 most striking resemblance to those of the sheep-fluke. The mere discovery 

 of such forms in a snail is, therefore, very far from being a proof that the 

 snail harbours the intermediate form of the sheep-fluke. 



The foregoing remarks allow us to proceed profitably to a consideration of 

 the preventive and remedial measures that may be successfully adopted by 

 Australian sheep-graziers. 



Remedie A.ND Preventive Measures. 



The various remedies and preventive measures which I shall propose are 

 based on our knowledge of the life-history of the sheep-fluke, as narrated in 

 the foregoing pages. After the reader has perused these proposals he will, 

 I think, agree with those who set a high value on the abstruse and difficult 

 scientific researches that have slowly led up to our present knowledge of the 

 nature and phases of the fluke. It will be seen that each remedy is based 

 on some fact in the life-history of the fluke — some fact that has become 

 known solely through the agency of scientific research. As this thought 

 comes home to us it inevitably raises the question, " Who are those 

 investigators who have wrestled so patiently and successfully with this 

 dark problem ? " Reader, it would lead too far afield if I should attempt 

 only to name and locate them. Many of them are dead — most of them are 

 unknown and unappreciated beyond a narrow circle of friends, while all of 

 them have gone practically unrewarded. How pathetic it is to compare the 

 great reward a later generation would willingly lavish on a discoverer or 

 inventor with the pittance meted out by his contemporaries, and how short- 

 sighted and poor-spirited are Ave, to be moved by such a noble impulse 

 towards the distant and dead, yet forget that we ourselves may be playing 

 the A^ery part of those mean old contemporaries. 



It must be remembered that in dealing with remedies we are obliged to 

 mention all the various Avays in which the fluke evil may be mitigated. No 

 person will, perhaps, be able to adopt all of the following suggestions ; 

 nevertheless, none of them are without their uses. Again, no one of them 

 is alone a sufficient precaution. So far as possible they should be all adopted 

 concertedly. 



