1 6 Veterinary Medicine. 



head and neck, or, as in birds, even show a preference for parts 

 (comb, wattles, legs), that are destitute of epidermic growths 

 (feathers). It would appear as if a special condition of the 

 system (youth), and the presence of excess of exudates and epi- 

 thelial debris, and of a special chemical condition of these materi- 

 als favored the growth of the cryptogam, which disappears from 

 the surface when the conditions are altered. The freer secretions 

 and desquamations in the young growing animal, the close air of 

 winter stabling, the accumulation of stable dust and dandruff, the 

 damp and darkness of the building, and the susceptibility attend- 

 ant on moulting have doubtless some effect in making these dis- 

 eases of winter and spring especially, while the opposite conditions 

 tend to their subsidence when turned out on spring pasture. 



A fungus parasite usually localizes itself mainly on the surface, 

 in the epidermis or epithelium where it can often be destroyed 

 with facility by local applications. When on the other hand it 

 colonizes the lining membrane of the air passages or alimentary 

 canal, or when, as in actinomyces or botriomycosis, it invades 

 solid tissues, the treatment becomes more complex and less certain. 



Diagnosis is based on the appearance presented to the naked 

 eye, but above all on the presence of the pathogenic cryptogam. 

 Scrapings or sections should be made of the most recent part of 

 the growth (on the skin the deepest portion). Oily matters 

 should be removed by steeping these once or twice in ether or ab- 

 solute alcohol. The specimens are then placed in a mixture of 

 equal parts of caustic potash or soda and water, with a few drops 

 of carbolic acid, and examined under a magnifying power of 200 

 to 500 diameters. The epidermic products are thus rendered 

 clear and translucent, while the unaffected spores and mycelia 

 stand out in groups and filaments. When they have invaded the 

 hairs the action of the alkali must be prolonged, but the effect is 

 the same. 



True to their habit of growth on dead organic matter these 

 cryptogams may be further cultivated in artificial media, best at a 

 temperature of 33" C. The various alkaline or neutral bouillons 

 may be employed — peptonized bouillon, infusion of turnip or 

 malt, or skimmed milk. These cultures are easily sterilized by 

 solutions of iodine, carbolic acid, oil of turpentine, chloroform, 

 corrosive sublimate, salicylic acid, or alcohol, offering suggestive 

 methods of treatment for affected animals. 



