88 VEGETABLE PARASITES. 



PART II. 



VEGETABLE PARASITES. 



The vegetable parasites of birds, so far as our present 

 knowledge goes, are few in number. These vegetable 

 parasites are minute microscopical fungi, about which 

 we know comparatively little. Three distinct families 

 of parasites are known attacking poultry, namely : — 

 (1) the Dermatophytes, which are cutaneous parasites, 

 such as Ringworm and the poultry-disease known as 

 Favus : (2) the Perisporiacece, or ' Moulds/ which 

 affect the air -passages and cause a disease known 

 as ' Mycosis ' : (3) the SaccJiaromycetes, which attack 

 the mouth, pharynx, and other parts of the alimentary 

 canal ; these are the cause of the ' Thrush ' in human 

 beings, calves, and poultry. 



In England there does not seem to be much loss 

 by these minute vegetable enemies. "When outbreaks 

 do occur, they are generally attributed to other 

 causes, owing to the incomplete knowledge of the 

 parasitic ailments of the birds. It must be remem- 

 bered that our knowledge is not very complete in 

 this subject ; but sufficient is known to be able 

 to identify the diseases caused by these vegetable 

 germs. 



The diseases of the skin produced by the vegetable 

 parasites are known under the generic name of 



