128 



BOTANY. 



214. To show the "runners" of the black mould. — If some 

 filter paper is placed by the side of the bread or other substance 

 in the moist chamber, some of the threads of the fungus may 

 be induced. to grow over on to it. If the mould is the species 

 illustrated in fig. ioo there may be seen " runners " like those 

 in the figure with clusters of the sporangia at certain points. 

 Certain threads of the mycelium grow along on the paper like 

 a strawberry ' ' runner ' ' does over the ground. Here and there 

 the mycelium touches the paper and forms little rootlets, and 

 also a group of the sporangia. It is because of this character that 

 the plant is called Mucor stolonifer, the stolon bearing mould. 

 Or the other name of " rhizopus " is given because it is " root- 

 footed. ' ' 



The black mould. 



Synopsis. 



Grows on old bread, decaying fruits, vegetables, etc. 

 Vegetative part ; delicate whitish threads, which 

 branch, and form a cottony-like mat, called the my- 

 celium. 

 Fruiting part ; upright stout threads bear black heads, 

 called sporangia. 



Several fruiting threads in a cluster, 



with rhizoids at base. 

 Sporangium. 

 Sporangium wall. 

 Columella. 

 Spores (or gonidia). 

 L Sexual stage not treated of here. 



Material. — Cultures of the black mould on bread or baked potatoes. See 

 paragraph 49 for making the cultures. 



Microscope, etc. 



If conjugation of a mould is desired, it may be purchased of supply com. 

 panies. 



Fruiting part. ■ 



