1915] 



ATKINSON PHYLOGENY IN THE ASCOMYCETES 



317 



tained by fusion of sister nuclei, or even by contemporaneous 

 growth of nucleus and cytoplasm, such as is well known to 

 occur in many other cases, for example in sexual cells, gonoto- 

 konts, etc. 



3. The phylogenetic relation of the ascocarp and cystocarp. 

 — If this principle of the resemblance between different types 

 of cystocarp and ascocarp has any force, it would mean that 

 the sac fungi had as many points of origin from the red algae 

 as there are points of resemblance between their fruit struc- 

 tures. I presume no one at the present time holds any such 

 view of the polyphyletic origin of the Ascomycetes. 



4. The phylogenetic relation of the trichogyne and sexual 

 apparatus of the Ascomycetes and those of the red algae. 

 The sexual apparatus of some of the Ascomycetes, particu- 

 larly the trichogyne, and the so-called spermatia, is generally 



conceded to be the 



strongest evidence 



in support of their 



phyletic relation to the red algae. This theory, however, re- 

 quires a jump from the simple trichogyne, a continuous pro- 

 longation of the egg of the red algae, to the complex, multi- 

 septate one of the Ascomycetes. It requires further the re- 

 duction of this trichogyne to a unicellular one, and then to the 

 simple gamete. It also requires the transition from free an- 

 theridia, or spermatia, to fixed ones, and from this specialized 

 condition to the simple gamete, thus finally attaining the gen- 

 eralized condition of the copulation of simple gametangia. 

 This appears to me to be a rather strained backward reading 

 of the evidence. 



ORIGIN OF THE ASCOMYCETES FROM FUNGUS ANCESTRY 



Although Sachs' suggestion of the relation of the Ascomy- 

 cetes to the red algae was received with favor by many stu- 

 dents at that time, and the doctrine has received a fresh im- 

 petus in recent years, it was not accepted by some of the 

 foremost students of the fungi at that time (Winter, 79; 

 deBary, '84). DeBary plead for the application of the 

 theory of descent which had come to be used as the basis 

 of classification for the higher plants. As a result of his ex- 

 tensive studies of development in the Phycomycetes and As- 



