CARPOSPOREM 



139 



are, in some cases, straight and prismatic, or they may be 

 dichotomous, or hooked (Fig. 

 252) at the free ends. 



i. Pyronomycetes. This 

 order differs from the preced- 

 ing in having the asci em- 

 bedded in deep cavities (called 

 perithecia) with narrow openings, instead of being com- 

 pletely enclosed in perithecia. The pyronomycetous Fungi 

 are very numerous, and exceedingly injurious not only to 

 plants, but to insects also. A common representative is the 



Fungus {Clavic&ps purpurea ; 

 Fig. 253), which produces 

 the Ergot on Eye and other 

 Grasses. In its earliest stage, 

 it consists of a mass of myce- 

 lium (Fig. 253, m), in and up- 

 on the young ovary. Conidia 

 (Fig. 253, con) are produced 

 in great abundance, which 

 quickly germinate. Follow- 

 ing the conidial stage, the 

 mycelium, at the base of the 

 ovary (Fig. 253, ov), assumes 

 a hard and compact form, 

 increases in size, bears a 

 horn-shaped and dark-colored 

 body, the so-called Ergot. 

 Such a compact mass of hy- 

 phse is called a sderotium. 



Fig. 252. The sporocarp (perithecium), with its appendages and two asci, of 

 Uncinula macrospara. Fig. 253. Cla-uiceps purpurea, the Fungus which pro- 

 duces the Ergot ; i?i, mycelium ; con, conidia ; ov, ovary. 



I 



°0 





253 



