The Collemaceae of Ohio 
39 
The sex organs grow, for most part, during two months in the spring 
and for the same length of time in autumn. These organs may be found 
in specimens not collected during these periods; but the cells are likely 
to be dead, and the parts of the archicarps collected out of season are 
not likely to have quite their natural form. The spermagonia likewise 
must be studied at the right time, since the spermatia decrease in num¬ 
bers and finally disappear entirely after the prime condition is past, while 
the basidia become considerably enlarged. The spermagonia usually ap¬ 
pear as minute protuberances, which are commonly some shade of yellow 
or brown. They occur most frequently on the lobes and near the 
margins, or at least externally to the areas occupied by mature apothecia. 
They may be seen easily with a hand lens, especially after the lichen and 
the algal host are moistened; but they are not easily distinguished, in 
gross morphology, from young apothecia, which have not yet ruptured 
the mass of structures which lie above them. There is no way of de¬ 
tecting the presence of archicarps through external appearance, but they 
usually occur toward the margins from the position occupied by the 
scattered apothecia. Sometimes, however, the archicarps are found 
within the region of the thallus occupied by the apothecia, and they rarely 
occur well toward the center of the thallus. The more central ones are 
likely tO' be past prime and more or less distorted. 
Owing to the uncertainty of finding the sex organs and their slight 
or infrequent taxonomic value, we have, after working them out labor¬ 
iously, decided not to burden the diagnosis with matter of so little value 
in determining species. Instead, we have given the results from studies 
of these organs toward the close of the paper where they may be acces¬ 
sible to those who may wish to consult them. Though the sexual tracts 
are not of sufficient diagnostic worth to warrant lengthening the diagnoses 
considerably in order to include them, it is true that critical workers on 
the Collemaceae must hereafter take these structures into account. Miss 
Bachman’s results (1 and 2) and our own findings from several regions 
widely separated (Figs. 14 and 20) prove that forms so much alike with 
respect to somatic characters and their method of modifying the algal- 
host colonies may differ so much with respect to the sexual tracts that 
they can scarcely belong to the same genera (Pis. Ill and IV). This 
means that critical workers on the Collemaceae must know at least the 
general nature of the reproductive tracts in every specimen in which they 
can be found in order to be reasonably certain that forms so much alike 
otherwise do not differ greatly with respect to the sex organs and their 
behavior. Some of the minor differences in size and form of the sexual 
