THE PHYSICS OF THE ASCUS JET 241 



will tend to become elongated. The first spore will have a 



FlG. 19. — Peziza repanda. A, a young unripe fruit-body. Natural size. B, an older 

 expanded fruit-body which was discharging spores. Natural size. C, a vertical 

 section through the disc of B showing the hyrnenium h, the subhymeniuni s, and 

 the excipulum e with an external brown layer b. Magnification, 40. D, two 

 septate paraphyses with clavate terminal cells. E, a ripe ascus containing eight 

 spores which are loosely attached to one another and are suspended in a subterminal 

 position by a filament probably composed of protoplasm. F, a contracted ascus 

 just after the spores have been discharged. G, the end of an ascus in which only 

 partial spore-discharge had taken place. A spore was making its exit endwise 

 through the ascus mouth. H, eight separated spores as seen near the mouth of an 

 ascus just after discharge into a fluid medium. The unilateral gelatinous invest- 

 ments, shown within the ascus at E, have now become very much swollen. I, a 

 spore which after discharge had fallen back on to the hyrnenium and had then 

 germinated. The germ-tube gave rise to two clavate conidiophores bearing minute 

 conidia. D-I magnification, ?> 17. 



higher velocity than the second, the second a higher one than 



Q 



