26 The North American Cup-Fungi 



From the fact that the spores of the species of many copro- 

 philous fungi do not germinate readily, it has been assumed 

 that it is not only possible but necessary that they pass through 

 the alimentary canal of the animal before they could be induced 

 to germinate. Many experiments have been conducted to show 

 that this is the case and there is little question that this process 

 does stimulate germination. 



The distribution of the spores in such forms is easily accounted 

 for. Growing as they do on dung in pastures, the spores which 

 are more or less sticky on being discharged from the ascus easily 

 adhere to blades of grass and other forms of vegetation. The 

 grass is eaten by cows or other animals and the spores gain 

 entrance to the alimentary canal and, on being released, are 

 ready for action. It is not unusual to find spores of coprophilous 

 fungi on leaves of living plants in the field. The writer once 

 spent considerable time trying to identify a supposedly parasitic 

 fungus from Bermuda on blades of grass only to find later that 

 they were the spore caps from Piloholus which adhered so closely 

 that they appeared to have grown there. 



16. Spore Germination 



The spores of many of the species of cup-fungi germinate 

 readily and without any special treatment. In some of the 

 species, however, as indicated above, the spores do not germinate 

 by the ordinary method. This has already been referred to in 

 the coprophilous forms, especially species of Ascobolus. The 

 members of this genus are not all coprophilous, some occurring 

 on wood and one species, Ascobolus carbonari us, on burnt ground 

 and still others on naked soil. 



On the assumption that the spores of the coprophilous 

 species must pass through the body of the animal in order to 

 stimulate them to grow, attempts have been made to simulate 

 these conditions by artificial means and favorable results have 

 been obtained by this method. 



Dodge in his researches on Ascobolaceae, referred to above, 

 tried many experiments and found that spores of several species 

 of Ascobolus, including Ascobolus carbonarins, could be made to 

 germinate in culture by heating them to a temperature of 50 

 to 70 degrees centigrade. The heat stimulus seemed to be a 

 favorable substitute for the chemical stimulus of the alimentary 

 canal. From this we might assume that Ascobolus carbonarius 



