The Origin and Development of the Apothecium etc. 
377 
laria Heppii Mull. Arg., and 0. leptoplxylla Tuck., he found no trace of 
carpogones or trichogynes and thought that the apothecia develop in a 
purely vegetative manner. From Forssel’s work it appears that even 
in the same genus the apothecia develop differently. Spermogonia are 
found in abundance in the gleolichens. 
Along with the sexual nature of liehen spermatia, the distinct origin 
of ascogenous liyphae from tliose giving rise to paraphyses continued 
to be a much disputed question. Hoping to get further evidence as to 
the origin of these two Systems of hyphae and also to get more light upon 
the development of the apothecia, Lindau (60) investigated a number 
of species in several genera of lichens. In all these forms — Anaptychia 
ciliaris Krb., Ramalina fraxinea Fr., Physcia stellaris Ayl., P. pulveru- 
lenta Ayl., Parmelia tiliaceae Hoffm., Xanthoria parietina Fr., Placodium 
saxicolum Krb., Lecanora subfusca Ach., and Lecidella enteroleuca Krb. — 
he found asci and paraphyses to have a distinct origin and observed a 
development of the apothecium similar to that described by Stahl for 
Collema. In Anaptychia ciliaris, many of the ends of the hyphae in the 
cortex, as well as the trichogynes, protrude from the surface of the thallus. 
Spermatia are attached to both; they can be easily separated by jar or 
otherwise from the cortical hyphae but not from the trichogynes. However, 
Lindau saw no fusion with the trichogyne and no later shriveling of tliis 
organ nor gelatinization of its walls. Yet no trace of trichogynes was 
found in old apothecia. In Ramalina fraxinea the ascogones are branched, 
but he did not observe whether each branc-h ends in a trichogyne. In 
Placodium saxicolum the ascogones are simple or branched. Here the 
branching is usually from the vegetative hyphae and each fork functions 
as a single ascogone. In Lecanora subfusca there is a branching of the 
trichogyne so that a single ascogone has two trichogynes. In Lecidella 
there is a division of an apothecium into a number of smaller ones whieh 
is very similar to the production of secondary apothecia described by 
Krabbe for Pertusaria leioplaca. As to the nature and function of tricho- 
gynes and spermatia, Lindau concluded nothing. 
Sturgis (76) in 1889 reported a vegetative origin for the apothecium 
in Sticta anthraspis Ach., S. amplissima, Nephroma tomentosum (Hoffm.) 
Krb., Peltigera polijdactyla (Aeck.) Hoffm., Heppia despreauxii (Mont.) 
Tuck., Pannaria molybdia (Pers.) Tuck., P. rubiginosa (Tlmnb.) Delis. 
and Hydrothyria venosa Russ. In these species Sturgis believes that 
asci and paraphyses arise from the same System of hyphae. For the 
Collemaceae whieh he investigated, Physma mülleri Hepp., P. compactum 
Mass., Collema pulposum Ach., C. nigrescens (Huds.) Ach., and Leptogium 
