Monld (Penidllium 8p.) 



Material. — Examine stale bread or cake, shoe-black- 

 ing, old leather, ink, preserves, etc., for the common blue 

 mould. If none be found, specimens may easily be raised 

 by moistening a piece of bread, covering it with a bell- 

 jar, and allowing it to stand in a warm place for about a 

 week. At the end of that time the bread will probably 

 be covered by a fine crop of moulds, and among them 

 the kind wanted. A decoction of prunes may be left 

 standing exposed to the air for a time, and PenicilUum 

 will almost certainly make its appearance. 



Schulze's solution, iodine, potash, Pasteur's solution 

 with sugar, watch-glass, fine forceps, hand -lens, com- 

 pound microscope, moist chamber, twenty per cent, glyc- 

 erine, and thirty per cent, alcohol will be needed. 



Method of lamination. — Look for PenicilUum grow- 

 ing naturally. Try to find how many different sub- 

 stances it infests. Compare specimens developed natu- 

 rally with those raised by cultivation. 



MOEPHOLOGT 



Nahed-eye Characters. 



a. General appearance. — Examine the coating of mould 

 found on the infested material. Do you find the 

 mould to be in several masses or in one ? What is 

 the color of the mould ? Do you find any varia- 

 tions of color ? If so, do' the various colors shade 



