V.] MOULDS. 39 



of the mycelium (examine the surface with a low 

 power); then the formation of aerial hyphse; finally 

 the production of new conidia. 



b. [Sow conidia in Pasteur's fluid in a moist chamber, and 

 watch from day to day; note the formation of eminences 

 at one or more points on a conidium; the elongation of 

 these eminences to form hyphse ; the branching and inter- 

 lacement of the hyphse.] 



B. MUCOR MUCEDO. 



1. Place some fresh horse-dung under a bell-jar and 

 keep moist and warm ; in from 24 to 48 hours its 

 surface will nearly always be covered by a crop of 

 erect aerial mucor-hyphse, each ending in a minute 

 enlargement (sporangium] just visible with the un- 

 assisted eye: it is this first crop of hyphae and spor- 

 anges which is to be examined. 



2. Snip off a few of the hyphse with a pair of scissors, 

 mount in water, and examine with 1 inch obj. 



a. Large unbranched hyphse, each ending in a 

 spherical enlargement (sporangium). 



3. Examine with J obj. 

 a. The hyphse. 



a. Their size; they greatly exceed the hyphse of 

 Penicillium both in length and diameter. 



ft. Their structure; homogeneous sac, granular 

 protoplasm, vacuoles: septa absent except 

 close to the sporange. 



7. Treat with iodine and magenta; the proto- 

 plasm is stained. 



