[Vol. 2 



336 



ANNALS OF THE MISSOURI BOTANICAL GARDEN 



hirsutum, Acetahula calyx, Exoascus deformans, and some 

 lichens). The origin of the ascus was correctly described in 

 a number of cases, but in the majority of cases at that time he 

 thought the young ascus arose by the copulation of two unicel- 

 lular gametes according to a method similar to the formation 



Fig. 8. Pyronema confluens: A, section of mature discocarp; B, group 

 of archicarps copulating with antheridia by means of the slender prolonga- 

 tion (trichogyne) of the ascogonium which is separated as a distinct cell; 

 C, pair of sexual organs copulating by means of the trichogyne cell, asco- 

 gonium at left, antheridium at right; D, showing multinucleate condition of 

 sexual organs and communication of antheridium and trichogyne. a, 

 antheridium; b, trichogyne; c, ascogonium. E, older stage of a similar 

 group of sexual organs after the antheridial nuclei have entered the asco- 

 gonium and the trichogyne nuclei have degenerated ; also showing early stage 

 of growth of ascogenous hyphae from the ascogonium; F, showing relation 

 of ascogonia, ascogenous hyphae, asci, and paraphyses in mature fruit 

 body. — After Harper. 



