GABPOPHYTA. 



199 



stools) or internal (in PufE-balls). There are about 10,000 

 species, which may be separated into two orders, the Gas- 



TEEOMYCETEiE and the HYMEIirOMYCETB^. 



362. The PufF-balls (Order 18. Gasteeomycete^).— 

 The plants of this order are saprophytes, whose spore-fruits 



Fig. 116.— Fruit of a Puff-ball. Natural size. A, exterior; B, section 

 showing the sterile base, with the gleba (sporiferous tissue) above. C, 

 two basidia, with spores, highly magniiied. 



{A, B, Fig. 116) are often of large size and usually more or 

 less globular in form. The spores are always borne in the 

 interior of more or less regular cavities, and from these 

 they escape by the drying and rupture of the surrounding 

 tissues. 



363. The yegetative filaments of PufE-balls penetrate the 

 substance of decaying wood, and the soil filled with decay- 

 ing organic matter. They are colorless and jointed, and 

 usually aggregate themselves into cylindrical root-like 

 masses. After an extended vegetative period the filaments 

 produce upon their root-like portions small rounded bodies, 

 the young spore-fruits, which increase rapidly in size and 

 assume the forms characteristic of the different genera. 



364. No sexual organs have yet been discovered, but 

 analogy points to their possible existence upon the vegeta- 

 tive filaments Just previous to the first appearance of the 

 spore-fruits. The spore-fruits are composed of interlaced 



