DISEASES OF POULTRY. 



57 



gillus glaucus, and Aspergillus candidus. Usually 

 these fungi are found in nature growing upon dead 

 organic matter; but they have great vegetative and 

 resisting power and are able to adapt themselves to 

 various conditions of existence. Many species of birds 



are affected by 

 them, the dis- 

 ease caused by 

 their develop - 

 ment having been 

 observed in pig- 

 eons, pheasants, 

 fowls, ducks, 

 geese and swans, 

 as well as in vari - 

 ous cage and 

 wild birds. Pam- 

 pered and deli- 

 cate birds are be- 

 lieved to be most 

 frequently at- 

 tacked. The dis- 

 ease may take on 

 the characters of 

 an epizootic and 

 attack a large 

 number of indi- 

 viduals. 



Symptoms. — In 

 the early stages 

 of the disease no symptoms are noticed, and it is only 

 after it has progressed considerably that these be- 

 come apparent. The affected birds do not follow the 

 flock; they are very weak, scarcely able to stand, and, 



Fig. 9.~DiagTammatic representation of the air" 

 sacs showingr their relation to each other, and to 

 the lungs. A, trachea; B, interclavicular sac; 

 C, D,E, F, extensions of the interclavicular sac; 

 <J, anterior thorocic sac; H, humerus; I, poster- 

 ior thoracic sac; J, entrance of bronchial tuem- 

 1)rane; K, abdominal sac. 



