56 



AGRICULTURAL AND INDUSTRIAL BACTERIOLOGY 



nearest the mother cell is the youngest. In other molds 

 spore formation results from the budding out of a cell (not 

 a pinching off) from the terminal cell. The spore then 

 grows to its full size, and from its tip another spore buds 

 out. A continuation of this process also results in the for- 

 mation of a chain of spores. In this type of spore forma- 

 tion, however, the chains are sometimes branched, that is, 



Fig. 37. — ^Mold spores (conidia). 1. Various types of unicellular 

 spores. 2. Types of spores with two cells. 3. -Multicellular 

 spores. 



more than qne spore may bud from a single cell. The 

 terminal cell of the chain is always the youngest. 

 The conidia developed by molds are of many shapes and 



Fig. 38. — Types of spoee production by molds. 1. Chlamydospores 

 of Mucor. 2. Conidia production in M ulleriella, no conidio- 

 phores produced, the conidia arising laterally directly from the 

 mycelium, 3. Urospora showing simple conidiophores. 4. Con- 

 idiophore of Aspergillus. 5. Conidiophore of PenicUlium. 

 (After Brefeld.) 



sizes. The simplest type of conidium is that which is sin- 

 gle-celled and oval or spherical in shape. Other single- 



