76 



RESEARCHES ON FUNGI 



phore under water with the help of a needle without much difficulty. 

 After such an operation has been effected, the columella, while still 

 attached to the subsporangial swelling, becomes exposed to view as 

 shown in Figs. 29, C, and 31. The narrow band of sporangium-wall, 

 left attached to the columella and subsporangial swelhng and sur- 

 rounding the base of the columella when the sporangium dehisced, 

 can then be clearly seen (Fig. 29, C, c). It has a dark appearance 

 owing to its being covered externally with numerous minute 



Fig. .32. — Pilobolus Kleinii. Level of abscission of the sporangium indicated by a 

 broken line. A, the top of a subsporangial swelling crowned by a ripe sporangium 

 which has dehisced ; the sporangium -wall has split transversely into a 

 convex upper portion b and a lower band c, and in the gap one can observe the 

 jelly a and the spores d. B, like A, but the sporangium has been stroked off 

 imder water, leaving behind the columella e and the basal band of the sporangium- 

 wall c ; s, the subsporangial swelling. C, like A, but with the sporangium shown 

 separate from the subsporangial swelling ; the separation has been effected at 

 the level of abscission ; the drawing serves to indicate that the basal band of 

 the sporangium -wall remains attached to the sporangium as a whole when this 

 is shot away. Magnification, 66. 



particles which, as shown by microchemical reactions, are crystals 

 of calcium oxalate. The particles extend over the surface of the 

 subsporangial swelling below the band of the sporangium- wall, but 

 are less closely packed and less conspicuous there. 



At the moment when a sporangium is discharged from the 

 sporangiophore, the wall of the subsporangial swelhng just under 

 the junction of the band of sporangium-wall and the columella 

 suddenly spHts transversely, so that the sporangium and the 

 columella are shot away together. The level of abscission of the 

 sporangium is indicated by a broken hne in Figs. 28 (p. 70), 30, B 

 (p. 73), and 32. A large drop of cell-sap remains attached to the 

 gelatinous ring and the columella as the projectile travels through 



