382 
Freda M. Bachmann 
tlie groups in otlier species in tliat eacli ascogone is separated from the ! 
others of tlie group bv liyphae forming a sheath. It is Baur’s opinion tliat 
Lind Airs “mass of parallel trichogynes” which grow toward the sur- 
face of the tliallus are the first parapliyses. Baur found 110 more than 
15 to 20 trichogynes and observed that these completely disappear. The ! 
vegetative hypliae between the ascogones give rise to the parapliyses. i 
These grow vertically upward toward the surface, growing through and 
replacing the cortex in exactly the same way that Lixdau described for 
the newly formed trichogynes. 
Baur finds that the carpogones of Solorina bear little resemblance 
to those of other lichens. They consist of thick hypliae with thin walls 
and dense contents. There is a gradual transition of vegetative liyphae 
into ascogones. The development of the apothecium is purely vege- 
tative, althongh the ascogenons liyphae come from the ascogones and 
the parapliyses from the vegetative hypliae between the ascogones. Xo 
spermogonia are produced. In Cladonia pyxidata (L.) Fr. the podetium 
has a purely vegetative origin; when it attains some size there appear 
on the margin spermogonia and groups of carpogones. The approxima- 
tely parallel vegetative hypliae between the trichogynes are increased 
by thin-walled, elongated liyphae growing up between, and so are gra- 
dually transformed into a layer of parapliyses. 
From the preceding paragraphs it will be seen that we liave in some 
lichens a fully developed and functional sexual apparatus consisting of 
ascogone, trichogyne, and spermatia, and in others an apogamous develop- 
ment of rudimentary carpogones lacking trichogynes, spermatia also 
being absent. In all lichens in which spermatia have been found by 
former students of the group, these cells are borne near the surface of 
the tliallus in large numbers in cup-like depressions (the spermogonia) 
as described by Tulasxe in 1850. The trichogynes wherever they have 
been found, grow up to the surface of the tliallus, protrude a short 
distance and there, in some cases certainly, in others very probably, 
fuse with the spermatia which are brought to them perhaps by rain 
as suggested by Stahl. 
In a recent preliminary paper, I (1) briefly described and figured 
the sexual reproductive organs as I have found them in Collema pul- 
posum (Beruh.) Ach. In this species the spermatia are not borne in super- 
ficial spermogonia, but instead are found few in number borne on lightly 
staining hypliae some distance below the surface of the tliallus. The 
trichogynes do not protude from the tliallus. They are more active 
than in other lichens, in that they grow entirely within the tliallus to 
