MOULD 299 



hyplias originate? How do they compare with 

 the others in shape, size, structure, etc. ? Do they 

 branch ? If so, at what points ? Do you find 

 more than one branch given off at one point? 

 Do the cavities of the aerial connect with the 

 cavities of the mycelial hyph£e? Are the cavi- 

 ties of the branches in communication with the 

 cavity of the main stalk ? 



G. The conidiophores. — Study the structure of the 

 terminal branches or conidiophores. Note that 

 each tapers to a short, slender stalk, or sterigma, 

 "which bears a series of spherical or oval spores, the 

 couidia. Draw. Study a single stalk of conidia. 

 Does it branch? Do you find any variations in 

 shape, size, and color among the conidia of the 

 same stalk ? If so, what position on the stalk do 

 the larger conidia occupy ? Do you find any 

 conidia which are not yet fully formed ? If so, 

 ■what is their position on the stalk ? Judging 

 from the facts just observed, what do you think 

 is the manner in which the conidia are formed ? 

 Study the structure of a single spore, using sucb 

 reagents as are necessary. Does it resemble in 

 any way the cells of yeast ? Draw. 



d. The sporocarp. — It is not likely that the student 

 will be able to find this organ on PenicilUwm 

 and work out its structure successfully. The 

 sporocarps of Eurotium, which usually grows with 

 Penicillium, may be used instead. These will 

 be found as small, bright-yellow bodies situated 

 among the mycelial threads. Examine one of 

 them under both powers. Note how it is at- 

 tached to the mycelium. Study the structure 



