220 DEVELOPMENT OF THE ASPERGILLALES 



cate mycelium from which are developed numerous erect hyphae. 

 In the common blue mould, Penicillium, these erect hyphae are 

 broom like (Fig. 142, B) and the spores are formed from the 

 tips of the branches vary much after the manner of the budding 

 of the yeast cells. The tip of a branch buds out into a spherical 

 cell that is finally cut off from the stalk, thus forming the spore 

 (Fig. 142, C). This process is repeated again and again just 

 below each successive spore and in this way chains of spores 

 are formed. It will be noticed that many single spores are found 

 instead of a large sporangium which contains many spores as 



Fig. 142. Formation of spores or conidia in the Aspergillales: A, spore- 

 bearing hypha of Aspergillus. B, hypha of green mould, Penicillium. C, 

 one of the terminal branches of B enlarged, showing manner of spore formation. 



in the case of Mucor. These spores are sometimes regarded 

 as sporangia which have become reduced in size and contain but 

 a single spore. In Aspergillus, a fungus common upon preserves 

 and upon herbarium plants that have not been sufficiently dried, 

 the spores are developed from very short branches that arise 

 from a bulbous swelling at the apex of the erect hyphae (Fig. 

 142, A). The color of the spores, as in Mucor, is the cause of 



