KUNKEL: SPORULATION IN MACROSPORIUM SOLANI 309 
fields of Maine. They all responded in like manner, producing spores 
in great numbers. The method has also been applied to other Macro- 
sporiums that do not fruit readily in culture. M. tomato, Cooke, a 
parasite of the tomato and M. daturae, Fautr., a parasite of the jimson 
weed, Datura Stramonium L. respond in the same way to the wound- 
stimulus. Although M. daturae fruits quite freely without this 
stimulus, the number of spores produced in any culture can be greatly 
increased by wounding. MM. tomato fruits even more sparingly than 
Fic. 4. Fruiting culture of Macrosporrum solani. This picture shows the 
spores more highly magnified and indicates their abundance in a wounded string- 
bean agar culture. XX 250. 
M. solant in unwounded cultures. When thoroughly wounded it 
bears spores in great numbers. 
The abundant sporulation of M. solani in culture makes more 
easy the study of its fruiting stages. The successive steps in the 
development of conidiophores and spores can easily be observed. 
The mature conidiophores are always several-celled. They may 
arise singly or in whorls, as is shown in Fig. 2. The typical conidio- 
