382 m MOULDS AND YEASTS 



forceps ; place it on a dry slide and examine it with a 

 low power of the microscope or a strong hand lens. 



(b) Mount some in a drop of water, and after tearing the 



hyphae apart with a couple of needles, examine it first 

 with a low power, noting the large number of 

 separate conidia and tangled hyphae. 



Then examine it with a high power, and make 

 drawings of the conidia and the hyphae with their 

 contents and septa. 



(c) Take a fresh piece of the mould and dip it in a watch- 



glass containing absolute alcohol, to which a drop or 

 two of strong ammonia have been added. 



Then transfer successively to a series of watch- 

 glasses containing 75 per cent., 50 per cent., 25 per 

 cent., and 10 per cent, alcohol respectively, leaving it 

 thirty seconds in each. 



Mount it in a drop of water, and examine it for 

 conidiophores with unbroken brush-like sterigmata and 

 chains of conidia. 



Make drawings illustrating the arrangement and 

 structure of the several parts observed. 



Measure the conidia and sterigmata. 



Ex. 166. Place a piece of Camembert cheese under a bell- 

 jar, or in a Petri dish, on some damp blotting-paper. After a 

 few days, examine the moulds which grow on it, in the manner 

 described in the previous experiment. 



Make drawings and measurements of the parts of the fungi 

 observed : compare with P. glaucum. 



Ex. 167. Examine the yellowish, orange, or brownish patches 

 on the outside of any Stilton cheese available for P. brevicaule. 



2. The genus Aspergillus. 



An almost equally ubiquitous group of fungi are 

 included in the genus Aspergillus. They are closely 

 related to the genus Penicillium> and, like the latter, the 



