14 BROOKLYN BOTANIC GARDEN MEMOIRS 



sporulation until the second or third cell of the new growth, would 

 carry the zygote to the level of that in Sphaerotheca, in the true 

 ascomycetes. 



4. Vegetative growth of the zygote with splitting of the same by 

 branching, thus multiplying the terminal branches of the zygote in 

 which free cell sporulation takes place, carries the zygote to the level 

 of Pyronema, Monascus, etc., in the true ascomycetes. 



5. Organization of a fruit body by formation of a peridium of the 

 interwoven terminal branches of the mycelium. This is already 

 realized in the complex zygocarp of Endogone, the peridium being on a 

 level with that in the Gymnoascaceae. 



6. Organization of a peridium by enveloping hyphal branches of 

 the type in Monascus, the Erysiphaceae, Aspergillus, etc. This feature 

 is already realized in the simple zygocarp of Endogone lactiflua. 



Relation of the Zygotes and Azygotes in Endogone 



Several species of Endogone are parthenogenetic (£. macrocarpa, 

 microcarpa, pisiformis, etc.), yet the "resting spores" are similar to 

 the resting zygotes of E. sphagnophila, ludwigii, etc., in all other 

 respects so far as known at present, with the exception of the number 

 of nuclei in the resting stage. According to Bucholtz the zygotes of 

 the sexual species, E. lactiflua and E. ludwigii, are binucleate in the 

 resting stage, while the azygotes of E. pisiformis, macrocarpa, micro- 

 carpa, etc., are multinucleate. However, the zygotes of the sexual 

 species E. sphagnophila, are probably multinucleate in the resting 

 stage. It is very probable that at the time of germination the zygotes 

 of E. lactiflua and E. ludwigii become multinucleate by successive 

 divisions of the fusion nucleus. It is, therefore, very likely that the 

 phenomena of germination, whatever the type of germination is for 

 Endogone, is the same in the sexual and parthenogenetic species. It is 

 quite evident that the branch in which the azygote is formed is the 

 morphological equivalent of a gametange, just as the sporangia and 

 gametangia of Monoblepharis , Saprolegnia, etc., are morphological 

 equivalents. If there were sex differentiation among the nuclei of 

 the zygotes followed by fusion, then the azygotes w^ould be strictly 

 homologous with the zygotes, in fact they would be zygotes. Bucholtz 

 (1912) regards the simple zygocarp of Endogone lactiflua as homologous 

 with the germ sporangium (carposporangium) of the Mucorales and 

 Peronosporales. In a certain degree this is true, but it is also homo- 

 logous with the zygote of the Mucorales and Peronosporales. In the 

 Mucorales the germ sporangium is external to the zygote while in the 

 Peronosporales it is internal. The germ sporangium of Endogone is 

 not known, it may be internal or external to the zygote. The zygote 



