484 BOTANICAL GAZETTE [DECEMBER 
spores are formed in certain angiosperms. It may well be sie all 
the conditions mentioned represent mere adaptations. 
In the lichens many-celled spores occur, which are at first always 
uninucleate; for example, those of Endocarpon. The embryo gameto- 
phyte is formed in the spore, which continues its growth when condi- 
tions become favorable. Each cell, however, of the multinucleate 
septate spore gives rise to a filament when the spore germinates. 
Each cell of a septate spore is comparable to a spore of Thecotheus, 
in which walls have not been formed until the nuclear divisions 
have been completed. Germination occurs in the one case before 
spore delimitation, and in the other case after spore delimitation. 
In either case, after eight nuclei are formed we are dealing with 
gametophyte structures. It is a matter of indifference when germina- 
tion occurs, or when spore delimitation takes place, so long as the 
triple division has occurred. The time of spore formation is a matter 
of adaptation to conditions, but the essential nature of the process seems 
to be the same in all genuine members of the group of Ascomycetes 
so far studied. 
SUMMARY. 
1. The fruit body of Thecotheus is formed from several ascogonia 
and is therefore a compound apothecium. 
2. The ascogenous hyphae arise from any or all of the cells of the 
ascogonium, and consequently the cells of the ascogonium are not 
connected by perforations through which the nuclei pass to enter the 
ascogenous hyphae. 
3. The ascogenous hyphae do not in this case constitute a synkaryo- 
phytic system. 
4. The asci arise from the subterminal cells of the recurved tips 
of the ascogenous hyphae, which cells are binucleate. 
5. The ascus nucleus is formed by the fusion of these two primary 
ascus nuclei. 
6. The ascus nucleus divides by triple division to form eight free 
nuclei, each of which after a period of rest and growth undergoes 
further division until thirty-two free nuclei are formed in the ascus. 
7. Spore delimitation follows the process described by HARPER. 
8. Each spore is uninucleate from the start, no nuclear divisions 
or septa being formed. 
