120 SOME MINUTE ANIMAL PARASITES 



In addition to loss of weight, the birds become 

 markedly anaemic, the comb, wattles, and cere being 

 pale and bloodless. The feathering is weak com- 

 pared with that of healthy birds, and the leg-feather- 

 ing often is ragged. The quills lose their rigidity to 

 some extent ; the sheen on the covert feathers is less 

 developed, and the replacement of nestling-down by 

 ordinary feathers is much retarded in diseased birds. 



Owing to the attacks of the parasite on the mucous 

 membrane of the food-canal, and especially of the 

 intestine, digestive troubles occur, and the faeces 

 voided by the infected bird are an index of its con- 

 dition. The dejecta are very pale, softer than usual, 

 and often of a sulphur yellow colour, occasionally 

 with a very offensive odour. At times the un- 

 fortunate birds have a discharge from their eyes and 

 ears, and a peculiar bluish tint appears in the skin, 

 being especially noticeable around the eyes. The 

 death of the victim of coccidiosis is often sudden, 

 and with little indication that decease is imminent ; 

 in fact, the birds may be feeding a few moments 

 before death occurs. 



Before detailing the direct effects of the parasite 

 upon the internal organs of the host, it would be 

 well to consider the life-cycle of the destroying 

 organism and the interrelation that exists between 

 the parasite and its host. 



In connexion with the life-cycle of Eimeria avium, 

 it must first be explained that while the disease is 

 known as coccidiosis, the parasite causing it is more 

 correctly known as Eimeria avium, rather than Coc- 

 cidium avium, the name Eimeria having been used 



