46 RESEARCHES ON FUNGI 



as it rounds off, in separating from the sporangiophore, tears away 

 the sporangium completely, so that in the projectile the sporangium 

 is at the bottom of the drop with the black cap undermost forming 

 an unwetted base to the drop." Thus Ingold holds that, from the 

 moment the sporangium is discharged, it trails behind the drop 

 which carries it forward. It seems most unlikely that the projectile 

 should rotate through 1 80° and no further. Rather we must suppose 

 that the sporangium and the drop begin to rotate at the moment 

 of discharge and continue to rotate as they progress through the air. 

 To become stuck to an obstacle by its gelatinous side it is not 

 necessary for the sporangium to strike the obstacle by that side. 

 As will be explained more fvilly in the next Chapter, the sporangium 

 is forced round into its final position — wettable gelatinous side 

 toward the obstacle and unwettable black convex side away from 

 the obstacle — by the drop at the moment the drop strikes the 

 obstacle and flattens out upon it. 



Ingold says that " the stalk and upper bulb of the sporangio- 

 phore contain a clear liquid except where the stalk joins the bulb ; 

 here a conspicuous zone of oil is invariably found. This oil appears 

 to the naked eye as a minute orange spot at the base of the sub- 

 sporangial swelling." These statements give the impression that 

 the oil, hke the cell-sap, is contained within the vacuole. As a 

 matter of fact the oil is located in a biconcave mass of protoplasm 

 {vide infra. Fig. 28, g), and it consists not of one large drop but of 

 numerous very tiny drops embedded in the protoplasm. 



Ingold also states that, when the sporangium is discharged, the 

 lower part of the sporangium- wall " partially breaks down." My 

 own observations do not support this view. Ingold failed to notice 

 that, when the sporangium dehisces, its wall spUts transversely 

 into two pieces : (1) a lower narrow band which remains attached 

 to the columella, and (2) a much larger convex cap {vide infra, 

 Figs. 29 and 30). He correctly illustrated the lower band of sporan- 

 gium-wall attached to a columella isolated from a discharged 

 sporangium, but failed to recognise it as such. 



