458 BOTANICAL GAZETTE [jtjne 



in the carpospores. In none of these forms is the nucleus in the 

 auxiliary cell reported to fuse with the nucleus entering it from 

 the carpogonium. Thus Hassencamp (3), Yamanouchi (20), 

 Svedelius (14), and Lewis (6) have found, in the forms studied 

 by them, that only one nuclear fusion occurs during fertilization 

 and the formation of the carpospores, and this is the fusion between 

 the nucleus of the spermatium and that of the carpogonium. It 

 would seem that the evidence is overwhelming against the occur- 

 rence of a second fusion in the auxiliary cell. Undoubtedly one 

 reason why Oltmanns' work has been questioned is the fact that 

 certain morphologists have for years cherished the theory that 

 a relationship could be established between the Ascomycetes and 

 the Florideae. The ascogonium of certain genera is remarkably 

 similar in structure to the carpogonium of some of the Florideae. 

 No other plants except those belonging to these two classes have 

 this kind of a female reproductive organ. According to some 

 workers, certain genera of the Ascomycetes are distinguished 

 from all other plants by the fact that two distinct nuclear fusions 

 occur during fertilization and the formation of the spores. If it 

 could be shown that a second nuclear fusion does actually occur in 

 the auxiliary cell of such a form as Dudresnaya or Dumontia, the 

 carpogonium with its trichogyne and long sporogenous filaments 

 with the carpospores at their extremities might be proved to be 

 homologous with the ascogonium of some form like Pyronema with 

 its trichogyne and long ascogenous hyphae bearing ascospores. 



It has been stated that in all probability the nuclei in the spo- 

 rogenous filaments of Dumontia are descended from the fusion 

 nucleus in the carpogonium. However, more evidence is to be 

 desired in regard to the origin of these nuclei. The sporogenous 

 nuclei in Dudresnaya purpurifera, D. coccinea, and Gloeosiphonia 

 (Oltmanns 9) are unquestionably derived from the fusion nucleus 

 in the carpogonium. In Dumontia, as in the 3 species of the Crypto- 

 nemiales studied by Oltmanns, there can be no doubt in regard 

 to the passage of a nucleus from a sporogenous filament into an 

 auxiliary cell. A nucleus is always present in Dumontia at the tip 

 of each filament. Tips of filaments are found lying quite near the 

 auxiliary cells. A similar filament is found fused to the auxiliary 



