[Vol. 2 

 322 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



haploid eggs by sperms from the normal pollen. 



This sterility of the archicarp, I believe, has been brought 

 about by its assumption more and more of a vegetative char- 

 acter. The formation of septa at the base of the ' ' trichogyne ' ' 

 in such forms as Pyronema and Monascus, which primarily 

 may have been the beginning of a transverse splitting of the 

 oogonium, would make more difficult the fertilization of the 

 basal portion of the archicarp. In Aspergillus repens the so- 

 called ** trichogyne, " or terminal cell of the archicarp, some- 

 times gives rise to ascogenous hyphae^ (according to Miss 

 Dale, '09). The basal portion of the two-celled archicarp, or 

 the basal or central portions of the several-celled archicarp, 

 seem to be the portions which have retained the function of 

 ascogenic cells where that function still resides in the archi- 

 carp. As the archicarp becomes longer, the sterile portion, 

 which is non-ascogenic, becomes longer and more septate. 

 This only increases the difficulties of the passage of the sperm 

 nuclei. 



The increasing vegetative character of the terminal portion 

 of the archicarp has given rise to the long, simple, multisep- 

 tate "trichogyne" of the lichens and many Pyremomycetes 

 and Discomycetes, as well as to the profusely branched multi- 

 septate trichogyne of certain Lahoulheniales.^ It is an inter- 

 esting fact that in many of the cases of the extraordinary 

 vegetative development of the terminal portion of the archi- 

 carp (the ''trichogyne"), antheridia and spermatia are en- 

 tirely wanting.^ 



The degeneration changes of the sterile portion of the archi- 

 carp (multiseptate and often also much branched ''tricho- 

 gyne") which are described as taking place after connection of 

 the spermatium with the receptive terminal cell (for lichens see 



^ It is worthy of note in this connection that Olive's studies ( '05 ) of Mon- 

 ascus led him to regard the "trichogyne," or terminal cell of the archicarp, as 

 the ascogonium, and the second cell, or ascogonium according to others, as a nurse 

 cell. 



^Thaxter ('96) says that when the spermatia do not become attached to the 

 receptive cell of the trichogyne the vegetative growth of the trichogyne is greatly 

 increased. 



^ (Lachnea cretea, according to Fraser, '13; in Teratomyces actobii, Thaxter, 

 '96, was not able to find antheridia.) 



