MORPHOLOGY OF THE ASCOCARP. 2/ 



as a several-celled structure from which the ascogenous hyphae arise. 

 We have thus a fusion of gamete cells in another typical discomycete. 



Baur (5) has added a further valuable contribution to his studies 

 on the development of the apothecia of the lichens, in which he estab- 

 lishes the existence of carpogonia and trichogynes in a further series of 

 forms. Especially interesting is the demonstration of carpogonia and 

 trichogynes on the margins of the podetia of Cladonia, which corrects 

 the mistaken, though generally accepted, conclusion of Krabbe that the 

 entire podetium is homologous with an apothecium. Baur also shows 

 that Wahlberg's recent conclusion that in Anaptychia the paraphyses 

 arise from the ascogenous hyphae is incorrect. The hyphae which sprout 

 from the carpogonium never form paraphyses. Baur also adds another 

 form, Solorina, to the list of lichens which seem plainly apogamous. 

 The lichens bid fair soon to become, if they are not already, the best- 

 known group of the higher fungi as to the actual facts in the develop- 

 ment of their fruiting organs. 



Claussen (16) has also made a most interesting and important con- 

 tribution to our knowledge of the ascocarp as a result of very carefully 

 conducted studies on a new species of Boudiera. By growing the fungus 

 in appropriate cultures he was able to follow the development of the 

 sexual apparatus and the fusion of the gametes in living material. The 

 apothecium of Boudiera takes its origin, like that of Pyronema, from 

 several pairs of gametes. The antheridium and oogonium are spirally 

 coiled together, and a trichogyne cell is cut off from the apex of the 

 latter. As in Pyronema, the fusion-pore between the antheridium and 

 trichogyne is more permanent, while the disappearance of the wall 

 between the trichogyne and oogonium is transient and much more diffi- 

 cult of observation. Claussen did not find this opening in sections, but 

 was able to determine the transitory disappearance of the wall between 

 the trichogyne and oogonium in living material. The ascogenous hyphae 

 arising from the ascogonium seem each to produce but one ascus which 

 is typical in all respects in its development. We have thus a further 

 case of an ascocarp which arises from a compounded sexual apparatus. 

 As Claussen points out, such discoveries as these will furnish data for 

 a much more satisfactory arrangement of the groups of the Ascomy- 

 cetes than is yet possible. 



Juel (52) has given a most interesting account of the nuclear phe- 

 nomena in the fertilization of Dipodascus. The gametes are multinu- 

 cleated, but only a single pair of nuclei fuse. By division of the fusion- 

 nucleus the spore-nuclei are formed. In view of Dangeard's attempt 

 to homologize each ascus of the higher Ascomycetes with a supposedly 



