PERSONAL VIEWS ON PHYLOGENY 187 



happens that those fungi possessing a trichogyne are 

 amongst the most highly evolved, morphologically, of 

 the Ascomycetes ; amongst such may be enumerated 

 Polystigma, Poronia, and Xy/aria, all furnished with a 

 complex stroma in which the perithecia are embedded. 

 Some have conidial forms, others chlamydospores. We 

 can beg a solution of this difficulty by assuming that all 

 the primitive types of trichogyne-bearing fungi, that repre- 

 sented the first start from the Florideae, have disappeared, 

 and that only the most highly evolved forms of this type 

 remain. Or secondly, we may assume that this particular 

 type of sexual structure appeared spontaneously in the 

 fungi, without any connection with Floridean ancestors. 

 But the matter does not end here. Blackman, as pre- 

 viously stated, has discovered traces of a rudimentary 

 trichogyne in the Uredineae, and this he considers as 

 suggesting close affinity with the Florideae. Blackman, 

 however, denies any affinity between the Uredineae and 

 the Ascomycetes ; hence, according to him, the former did 

 not derive their trichogyne from the latter. Here again 

 we are reduced to the alternative stated above. Either 

 the Uredineae represent a second new and independent 

 origin from the Florideae, or the trichogyne, if it in reality 

 exists, was a spontaneous development in the Uredineae. 

 Finally, in Thaxter's Laboulbeniaceae, which he considers 

 as belonging to the Ascomycetes on account of the sexually 

 produced spores being formed in a mother-cell or ascus, 

 the sexual organs are in absolute agreement with those of 

 the Florideae, as is also the vegetative part, where proto- 

 plasmic continuity is so very conspicuous. This group, by 

 common consent, is aloof from all other known Ascomy- 

 cetes, and is yet further removed from the Uredineae, and 



