273 



bough with a croak of satisfaction and remains quite contented; he doze 

 away the greater part of the daylight, hut is always ready for me ill the 

 evening. 



To anyone desirous of keeping this uncommon cage bird I should 

 certainly advise their taking or obtaining one before it is a week old ; they 

 will then gape for food more readily and become very tame and interesting 

 in captivity. 



ftbc Contagious ^Diseases of Biros. 



By Henry Gray, M.R.C.V.S., Kensington, W. 



The contagious or transmissable diseases of the bird are 

 very numerous and important, not only from a scientific, but also 

 from a practical, point of view, as the majority of bird fanciers, 

 aviculturists, and poultry farmers can testify. 



Formerly they were divided into contagions and infectious, 

 the former being confined to those diseases that were contracted 

 by direct or immediate contagion, and the latter to those that were 

 supposed to be conveyed by the agency of the air. Since the true 

 nature of the transmissable diseases are now known to be due to 

 living organisms, these two terms are applied to one and the 

 same thing and are interchangeable. 



A contagious disease may therefore be defined as one that 

 is capable of being conveyed by direct contagion, as rabies or 

 contagious pleuropneumonia of oxen ; or by indirect ox mediate 

 contagion as anthrax, Asiatic cholera and typhoid fever. The 

 infectious or contagious element or virus is spoken of as the 

 eontagium, contagion, infection or materia morbes. 



The above terms are also applicable to the malarial (piro- 

 plasmoses) and the surra (trypanosomiases) classes of disease 

 where, in the majority of instances, gnats, ticks, flies, fleas, lice, 

 etc., play an important role in their transmission, and also form 

 intermediary hosts for the causal organism, which generally 

 undergoes certain changes in these (the hosts) so as to be con- 

 verted from a comparatively harmless into a most virulent 

 material when introduced into the system of the animal by the 

 puncturs °f the insect or acarus. 



Many of the tropical, sub-tropical, and even a few of the 

 European diseases of man, mammals and birds are communicated 



