84 



BOTANY. 



very large sterile cells (E, x), projecting far beyond the others, and often 

 reaching the neighboring gill. 



Similar in structure and development to Coprinus are all the 

 large and common forms ; but they differ much in the position 

 of the spore-bearing tissue, as well as in the form and size of 

 the whole spore fruit. They are sometimes divided, according 

 to the position of the spores, into three orders : the closed- 

 fruited (Angiocarpous) forms, the half- 

 closed (Hemi-angiocarpous) , and the 

 open or naked-fruited forms (Gymno- 

 carpous). 



Of the first, the puff-balls (Fig. 49) 

 are common examples. One species, 



FIG. 49. Basidiomycetes. 



A, common puff-ball 

 (Ly coper dori). B, earth 

 star (Geaster). A, x . 



B, one-half natural size. 



FIG. 50. Birds'-nest fungus (Cyathus). 

 A, young. B, full grown. C, section 

 through B, showing the " sporangia " 

 (sp.). All twice the natural size. 



the giant puff-ball (Lycoperdon giganteum), often reaches a 

 diameter of thirty to forty centimetres. The earth stars 

 (Geaster) have a double covering to the spore fruit, the 

 outer one splitting at maturity into strips (Fig. 49, . B) . 

 Another pretty and common form is the little birds'-nest 

 fungus (Cyathus), growing on rotten wood or soil containing 

 much decaying vegetable matter (Fig. 50). 



In the second order the spores are at first protected, as we 

 have seen in Coprinus, which belongs to this order, but finally 



