260 THE GROUSE IN HEALTH AND IN DISEASE 



Grouse. Examination of sections of the gut of the Grouse, especially of sections 

 stained with iron-hsematoxylin and iron-hsematoxylin followed by Van Gieson's 

 stain, reveals the presence of numerous bacteria, which are present, not only in the 

 lumen of the gut, but forming a layer along the striated edge of the columnar 

 epithelial cells, and also are found in lesions left by the outward passage of gametes 

 and merozoites. These bacteria may have a harmful effect on the tissues invaded, 

 and there is evidence to show that they gain access to the tissues very early, the 

 sporozoites and merozoites acting, in fact, as inoculating needles, whereby the 

 injurious bacteria are passed into the tissue of the gut, whence, by way of the 

 blood and lymph, they can reach other organs. Further, the denudation of the 

 epithelium of the gut allows of easy entry of bacterial agents of infection. 



In connection with the action of bacteria in the disease of fowls known as 

 "white diarrhoea," there are two opposing views. Morse (1908), working in 

 America, has investigated white diarrhoea in fowls and other birds, and always 

 found intestinal Coccidiosis. Hadley (1909), also working on the subject, found 

 not only intestinal but also hepatic Coccidiosis in fowls suffering from white 

 diarrhoea. Morse notes the presence of bacteria in the gut, and thinks that they 

 may gain access to the system on account of the denudation of the gut epithelium. 

 Rettger (1909), on the other hand, considers that white diarrhoea is due entirely 

 to a bacterium, Bacterium septicemice gallinarum or Bacterium pullorum. 



Probably both of these conflicting views are right as far as they go, but 

 separately they may only partially explain the cause of " white diarrhoea." Drs 

 Cobbett and Graham-Smith have shown (1910) experimentally that bacteria may 

 be inoculated by means of Coccidia, and find their way into the internal organs 

 probably by way of the portal vein (vide chapter xii. p. 295 et seq.). The agency of 

 parasitic worms and Coccidia in causing lesions of the mucous membrane through 

 which harmful bacteria may enter is of far-reaching importance, and probably of 

 wide application in the elucidation of certain intestinal diseases. 



Morse's paper gives much valuable information regarding treatment of Coccidiosis 

 and brief notes on intestinal Coccidiosis of various birds. Game birds other than 

 Grouse are susceptible to Coccidiosis, for M'Fadyean reported Coccidiosis in 

 Pheasants in 1893-1894. At the time of correcting proofs of this article I am 

 engaged in investigating Coccidiosis which is causing the death of many young 

 Pheasants in various parts of England. 



The onset of sporogony of E. avium means, as a rule, either the recovery or the 

 death of the infected chick. When the oocysts pass out from the body of the host, 



