248 



ESSENTIALS OF BOTANY 



After from three to six hours examine a drop from the surface of 

 the liquid with m.p. After about twenty-four hours examine another 



portion of the mold from the 

 surface of the liquid. Note : 

 (c) The beginning of for- 

 mation of hyphse and their con- 

 tinued development. Draw. 



In a prepared slide study 

 the conjugation of mold hy- 

 phse and the formation of 

 zygospores (Fig. 173). 



321. Discussion. — The 



bread-mold is a typical 

 saprophytic fungus. In 

 its structure, consisting 

 of a much-branched and 

 extremely large continu- 

 ous protoplast with many 

 nuclei, it considerably 

 resembles Vaucheria. Its 

 reproduction is of two 

 kinds, — asexual, by the 

 formation of spores within 

 a spore-case, and sexual, 



1, threads in contact previous to con juga- by the Conjugation of 

 tion; 2, cutting off of the conjugating • .i • i i 



cells a from the threads 6; 3, a later Similar-appearmg threads 



stageof the process; 4, ripe zygospore; (gametes) forming zygo- 

 5, germination of a zygospore and rpi .-ri- it'qx 



formation of a spore-case. (l-4magni- SporeS. ihese (-c Ig. 17 o) 



fied 225 diameters ; 5, magnified about are not aS freouentlv pro- 



CO diameters.) , ^ , , ^, , , , 



duced by the bread-mold 



as by some other closely related genera. 



The formation of the asexual spores in spore-cases is 



similar to the mode already mentioned in yeast fungi 



Fig. 173. Formation of Zygospores 

 in a Mold (Mucor Muc'edo). 



