72 



BOTANY. 



spore sacs colored a beautiful blue, so that they are readily distinguish- 

 able. 



The development of the spore sacs may be traced by carefully crushing 

 the young spore fruits in water. The young spore sacs (Fig. 43, E i) are col- 

 orless, with granular protoplasm, in which a nucleus can often be easily 

 seen. The nucleus subsequently divides repeatedly, until there are eight 

 nuclei, about which the protoplasm collects to form as many oval masses, 

 each of which develops a wall and becomes a spore (Figs. u-iv). These 



FIG. 43. A, a small cup fungus (Ascobolus) , x 5. B, young spore fruit, x 300. 

 ar. archicarp. C, an older one, x 150. ar. archicarp. sp. young spore sacs. 

 D, section through a full-grown spore fruit (partly diagrammatic) , x 25. sp. 

 spore sacs. E, development of spore sacs and spores: i-in, x 300; iv, 

 x 150. F, ripe spores. G, a sterile filament (paraphysis) , x 300. H, large 

 scarlet cup fungus (Peziza) , natural size. 



are imbedded in protoplasm, which is at first granular, but afterwards 

 becomes almost transparent. As the spores ripen, the wall acquires a 

 beautiful violet-purple color, changing later to a dark purple- brown, and 

 marked with irregular longitudinal ridges (Fig. 43, F). The full-grown 

 spore sacs (Fig. 43, E, W) are oblong in shape, and attached by a short 

 stalk. The sterile filaments between them often become curiously en- 

 larged at the end (G). As the spore fruit ripens, it opens at the top, and 



