286 BOTANICAL GAZETTE [NOVEMBER 
hyphae carries these knots to the upper portion of the ascocarp 
near the surface and separates them from one another. The 
ascogenous hyphae arise from these structures. They evidently 
represent some form of sex apparatus, but because of their lack of 
conventional trichogynes and their irregular habit, NIENBURG 
hesitates to give them the full status of typical ‘“‘carpogones.” He 
says: “‘Ich glaube deshalb, dasz regelrechte Trichogyne bei Sphyrid- 
ium nicht mehr angelegt werden, sondern dasz wir hier reduzierte 
Gebilde vor uns haben, die wahrscheinlich friiher als Empfangnisap- 
parate gedient, heute aber diese Funktion aufgegeben haben.”’ 
In Baeomyces the young fructification is sunken in the thallus 
and is distinguished as a mass of hyphae more closely interwoven 
than those of the thallus. At the center of this mass appear certain 
enlarged, deeply staining threads which are the ‘‘generativen 
Hyphen,” and which are the source of the ascogenous hyphae. 
NIENBURG’S uncertainty in the interpretation of these bodies is 
indicated in the following quotations: ‘‘So ist zu vermuten, dasz 
auch hier auf sehr friihem Stadium, Askogone als Verzweigungen 
der vegetativen Hyphen gebildet werden, die man nur mit unsern 
Mitteln von den iibrigen Gewebe—dem askogenen wie dem vegeta- 
tiven—nicht deutlich unterscheiden kann. ... . Vielleicht sind die 
dunklen Hyphen in den Kniueln der Fig. 17 solche Askogone, 
vielleicht sind es aber auch schon askogene Hyphen.” He decides 
that they may represent carpogonia, but if so, that they are very 
much reduced in Baeomyces, which he regards as an apogamous 
form. It is to be noted, however, that ascogenous hyphae still 
arise from these bodies even if they are structurally reduced. 
These brief reviews indicate how close is the correspondence in 
the history of the fertile system between some of the disco-lichens 
and of the Geoglossaceae. In both groups the procarps are nu- 
merous; they have, in general, the same type of structure; and in 
both are formed at a more or less advanced stage from a system of 
threads which makes its first appearance while the ascocarp is very 
young. 
It is interesting that in both groups parallel series are found 
showing comparable stages in structural reduction. In the lichens 
we have a graded series in Icmadophila, Sphyridium, and Baeomyces. 
