The Origin and Development of the Apothecium etc. 
379 
dcveloped but bearing many apotliecia. Since in the former carpogones 
are abundant, Baur attributed the failure to produce apothecia to the 
absence of spermogonia, which are always to be found on those thalli 
producing apothecia or on thalli in close proximity to these. The cross 
walls of the carpogone are not punctured, but like those of the vege- 
tative hyphae usually show an easily recognizable pit. The cells of the 
young carpogone are uninucleate. In four cases Baur succeeded in 
tracing the trichogyne to the tip, and here he found that the spermatium 
which had fnsed with the trichogyne was empty. Because of the small 
size of the spermatia, he was not able to see a continuity of cell contents 
of trichogyne and spermatium. Spermatia were always found on the 
trichogynes of those carpogones which developed further and never on 
those which disintegrated. After fertilization, deeply staining bodies in 
the trichogyne cells are probably the remains of the disintegrating nuclei. 
The cross walls of the lower trichogyne cells are less swollen and plainly 
punctured. In a number of cases he believed the original cross walls of 
the ascogone to be punctured. Those walls which are formed later he 
found to be entire. The number of ascogone cells is increased by inter- 
calary growth and later the ascogenous hyphae brancli from these cells. 
The cells of the ascogenous hyphae are uninucleate. The paraphyses 
brancli from the basal cells of the carpogone; the cross walls of these 
cells are not perforated. 
In 1899, Lindau (61), from a study of Gyrophora cylindrica, came 
to the eonclusion that the function of the trichogyne in lichens is merely 
that of a boring organ to break a way through the cortex. He believed 
that the trichogynes are increased in number until they form a mass 
of parallel erect filaments. He proposed the name “terebrators” or 
“terebrator hyphae” for the numerous trichogynes. 
Darbishire (25) described in some detail the development of the 
apothecium in Pliyscia. He described all the cells of the carpogone as 
connected by a slender but easily recognizable plasma thread. Because 
of the narrowness of the spermatium, he could not be certain of a Con- 
nection between this and the trichogyne. In every case in which the 
carpogone had ceased to develop or had returned to a vegetative condi- 
tion, the trichogyne bore no spermatia. After fertilization the cells of 
the coil beeome connected by broad plasma Strands, so that they come 
to form practically a multinucleate single cell in each swelling of which 
is a nucleus. From these swellings, — the original cells of the carpo- 
gone — branched cells grow out, the end branches of which are the asci. 
It appears that after fertilization no more cross walls are formed in the 
