The morphological relationships of the Florideae and the 
Ascomycetes 
B. O. DopGEe 
(WITH THIRTEEN TEXT FIGURES) 
In recent years our knowledge of the structure and life 
processes of many species of algae and fungi has been increased by 
general morphological studies frequently supplemented by critical 
cytological investigations. The later literature contains a vast 
amount of data bearing more or less directly on the question of 
the phylogenetic relationship of the Florideae and Ascomycetes. 
Harper has clearly distinguished between the questions of morpho- 
logical relationship and those relating to the special functional 
activities of the initial organs of the ascocarp. 
In the present paper I shall still further discuss the morphology 
of the various reproductive structures of the Florideae and As- 
comycetes in the light of my recent observations on the trichogynes 
and ascogonia in various members of the Ascobolaceae and related 
forms (37). Practically all the recently accumulated evidence 
favors the view that the Ascomycetes are a monophyletic group 
and have been derived from the red algae. I have brought to- 
gether in the form of diagrams the results of both recent and older 
work bearing on this question. The transition from the conditions 
in the red algae to those in the Collemaceae as described by Stahl 
(86) has been made much clearer by the work of Miss Bachmann 
(2, 3) in her studies on Collema pulposum. 
Brefeld’s doctrine that the Ascomycetes have been derived from 
the P hycomycetes through the evolution of the sporangium into 
the ascus is of course untenable, though in a somewhat modified 
form it has been recently revived by Bucholtz (21), who regards 
Endogone as a true Phycomycete in which the fruit resulting from 
the fusion of the nuclei from two unequally differentiated sex cells 
is a ‘“‘zygosporocarp.” The short time in which the sex nuclei 
travel together as a pair out of the odgonium directly into the sac- 
like outgrowth of the odgonium where they fuse, suggests to 
Bucholtz a primitive binucleated condition such as might have 
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