48 RESEARCHES ON FUNGI 



of water and also by occasionally spraying the dung-balls or pouring 

 water on the zinc floor. 



After the dung had been in the chamber for a few days, usually 

 but not always Piloboli began to appear upon it ; and often many 

 hundreds or even thousands of fruiting structures came to maturity 

 each day for several days in succession. The sporangiophores 

 exhibited the usual positive heliotropism, in consequence of which 



'. , .•■ .•♦,« •."• •••♦• . •.•*./. 



• .-. /•.: • . •.. ... ..-...• ... •» • . • •.••. 



.*. -^ • • . • *' .•••■ • . ^ \ . • •••••. "i 



■ ' .♦ .• .• . •. ■• . • • • •;.».••••. '^^ 



... • • • .• . • • .. .• • 



•••••■ • •* . • ;.-.». u'.' •• . ,, . . 



* •, • . . • . • . • • • .•..•-•• 



I •••■•.. • . • .• 



• • • 



' • . . • • . '»•••; . • • . • . • . . V 





i 



• ' :• •. 





• . • 



• • • ■ ■ 







. • . • 



,. • » 



Fig. 17. — Sporangia of Pilobolus longipes which were shot on to a sheet of 

 white paper set against the best-ilkiminated side of a large glass chamber in 

 which numerous fruit-bodies had come up on dung introduced there a few 

 days before. The large drop of cell-sap which accompanied each spor- 

 angium was absorbed by the paper, so that the sporangia have not run 

 together in groups as they do on a glass surface but have remained where 

 they landed. Natural size. 



they shot off their sporangia toward the side of the chamber through 

 which the strongest light entered. These projectiles adhered to 

 the glass where they struck, and thus a very large number of them 

 came to dot its surface (Fig. 17). 



In other cultures horse-dung balls were spread over the floor of 

 an almost cubical glass chamber (base 20 X 21 inches, height 24 

 inches). Here, as in the other large glass chamber, there was a 

 considerable body of air above the culture medium, and thus 

 aeration of the dung was provided for. The cultures in this chamber 

 were very successful. As an example one may be described. On 



