96 LABORATORY AND FIELD* EXERCISES 



b. Mount the above specimen in glycerin and alcohol and 



determine the relation of the sporangia to the hyphte. 

 What is the structure of a sporangial head ? What 

 is the nature of the contents of the young, light-colored 

 sporangia ? Consult Fig. 141 of text. 



c. Bead -the text 011 asexual reproduction and spore forma- 



tion in Rhizopus. Demonstrate as many of the stages 

 of spore formation described in the text as you can. 



d. Draw at least two stages of young, light-colored sporan- 



gia, including one in which spores are being formed. 



2. Mature sporangia and spores. Study mature sporangia and 



note the columella, the sporangium wall, and the spores. 

 What is the color and structure of the liypha which bears 

 mature sporangia ? Do you find the stolons and rootlike 

 hyphse connected with the liypha which bears the sporan- 

 gium ? See the text under Habit of Eliizopus. Draw 

 a mature sporangium and show its connection with 

 the main mycelium. Indicate stolons and rootlike out- 

 growths at the base of a sporangium-bearing liypha. 



3. Sexual reproduction. B material is available, demonstrate 



stages in the sexual process of Rliizopus. Read the text 

 on sexual reproduction. Demonstrate suspensors, game- 

 tangia, and zygotes, if seen in your material. Draw 

 stages observed in sexual reproduction. Label correctly. 



4. Life history. Write a graphical life history of Rliizopus 



similar to that already outlined for Spirogyra and other 

 green plants. 



PENICILLIUM AND ASPERGILLUS 



1. Habitat and habit. See the general nature of molds 



previously studied. 



2. Mycelium structure. Remove small portions of the myce- 



lium of a blue mold, mount, and study. Has it the same 



