330 ANNALS OF THE MISSOURI BOTANICAL GARDEN 



[Vol. 2 



Relation between the fusions of procarp and auxiliary cells, 

 and those of archicarp cells. — Several persons have made the 

 interesting suggestion that certain similarities between the 

 events which take place in the fusion of one or more of the 

 middle or basal cells of the procarp with an outgrowth from 

 the carpogonium, either direct, or through the medium of an 

 auxiliary cell, as represented in Erythrophyllum, Harvey ell a, 

 Callithamnion, etc. (third, fourth and fifth types mentioned 

 above), and those occurring in the fusion among themselves of 

 the middle or basal cells of the archicarp prior to the forma- 

 tion of the ascogenous threads, may be evidence of a phylo- 

 genetic relationship between the red algae and Ascomycetes. 

 Thus Baur ('98) suggests that the first fertile cell of the sev- 

 eral-celled ascogone of Collema crispum may be the egg cell, 

 that this may be fertilized by the entrance of the sperm nu- 

 cleus and its fusion with the egg nucleus. This fusion nucleus 

 may now divide. The other cells of the ascogone below the 

 egg are conceived of as auxiliary cells into each one of which 

 a nucleus resulting from the division of the fertilized egg 

 nucleus migrates after pore formation in the intervening 

 walls. 



In an interesting paper on the morphological relationships 

 of the Florideae and Ascomycetes, Dodge ('14) emphasizes 

 this theory by pointing to a number of cases in the lichens 

 and other Ascomycetes where fusion, or pore connections, are 

 known to occur between the ascogenous cells of the archicarp 

 where more than one cell gives rise to ascogenous hyphae. 

 Examples among the lichens are Collema crispum (Baur, '98), 

 Physcia pulverulenta (Darbishire, '00), Anaptychia ciliaris 

 (Baur, '04), and Collema pulposum (Bachmann, '13), while 

 among the other Ascomycetes may be mentioned the follow- 

 ing: Ascobolus (Harper, '96. Here there is but one asco- 

 genous cell which gives rise to the ascogenous hyphae, but pore 

 formation in intervening walls permits intercommunication 

 between several adjacent cells in the middle of the archicarp. 

 The species is not given), Ascophanus carneus (Cutting, '09), 

 Lachnea cretea (Fraser, '13), Poly stigma rubrum (Nienburg, 

 '14). 



