246 



APPLIED BACTERIOLOGY 



arranged the sterigmata. The latter two organisms grow 

 best at blood-heat, when they soon overgrow the nutrient 

 medium owing to their rapid growth. 



Aspergillus Flavescens and A. Fumigatus. — The former is 

 distinguished by its well-marked fructifications and greenish 

 colour of its culture, the latter by its fine fructifications 

 and ash-gray fur. On gelatine plates the filaments grow 

 rapidly into the medium, causing its liquefaction. Both 

 organisms grow at blood-heat. Both are pathogenic, 

 growing in various parts of the body — particularly the ear, 

 producing the disease known as otomycosis ; they have been 

 also found growing in the lungs and on the nasal mucous 

 membrane. The spores cause the death of rabbits on intra- 

 venous injection. 



Penicilliuin Glaucum. — The Penicillium glaucum is the 

 very common green mould seen on the bark of trees, old 

 walls, etc. It grows in the form of locks of cotton-wool, 

 and during sporulation forms a green fur of a peculiar 

 musty odour. The mycelium consists of horizontally 



Fig. 



■Penicillium Glaucum. 



arranged straight or slightly undulating jointed filaments, 

 from which the spore-beariag hyphee stand vertically up, 

 dividing at their upper ends into forks (basidia), from which 

 fine processes branch off (sterigmata) in the shape of a hair 



