FORMATION OF SPORES 



singly, as in Peronospora^ Botrytis, etc., in clusters, capitate, 

 from the swollen apex of a hypha, as in Cephalosporium ; 



FIG. 21. Cercospora circumscissa^ a fungus whose conidial fruit consists 

 of a single conidium produced at the tip of a short, unbranched conidio- 

 phore. i, peach leaf showing blackened spots caused by the fungus. The 

 small circular patches of leaf tissue killed by the fungus soon dry up and 

 fall, leaving a number of holes in the leaf, hence the popular name of 

 'shot-hole fungus.' 2, a cluster of conidiophores bearing septate conidia. 

 Fig. i, nat. size; fig. 2, mag. 



or in chains, concatenate, as Penicillium, Cystopus, Aegerila, 

 etc. When conidia are produced in chains the order of 

 development may be basipetal, the youngest conidium 



