COCCIDIOSIS 117 



suddenly with but little indications beforehand as 

 to disease, and in England young fowl-chicks and 

 three-parts-grown pullets have been known to die in 

 hundreds within a few days. 



Though such havoc has meant very serious 

 financial loss both to moor-owners and to poultry- 

 raisers, yet the cause of the trouble, particularly 

 among young birds, received very little attention 

 until 1908, when one of us, working with the Grouse 

 Disease Inquiry, investigated the cause of the 

 dwindling of young stock, and found that the deaths 

 of the grouse-chicks were due to a minute protozoal 

 parasite known as Eimeria avium. Further work 

 has shown that the maladies known to poultry- 

 breeders as " white scour," " scour," " white 

 diarrhoea," and, latterly, " enteritis," are due to 

 the same organism. 



The genus Eimeria is not restricted to birds, how- 

 ever, for another form infects and kills rabbits ; yet 

 another is parasitic in cattle, and a few cases are 

 known in which a parasite similar to that of the rabbit 

 has produced fatal effects in human beings. The 

 human parasite is possibly the same as that which 

 infests rabbits, and there is the likelihood that the 

 eating of the livers of rabbits suffering from cocci- 

 diosis has resulted in its transference with fatal 

 results to the human host. The livers of such in- 

 fected rabbits show white spots filled with a milky 

 fluid. The great range of distribution of these 

 parasites, then, is sufficient to invest them with con- 

 siderable interest, and this is augmented by an 

 investigation into the many forms assumed by the 



