The Origin and Development of the Apothecium etc. 
371 
differ from these other reproductive bodies in that they will not germinate. 
He believed the spermatia to be male cells and the asei, female cells. 
A very extensive work by Lindsay (59) on the spermogonia and 
pycnidia of lichens appeared in 1859. Tliis work has been criticized by 
Glück (43) as more extensive than exact. In bis first paper Lixdsay 
described and figured the spermogonia as to form, position, eolor, size, 
number and structure. His distinction between spermogonia and pycnidia 
is u one of convenience — one depending on the difference in character 
of the contained corpuscles, — not one as yet founded on essential differ- 
ences in function.” The contents of the pycnidia, the stylospores, differ 
as Lindsay sees them front spermatia in tlieir larger size and fewer number. 
He has described the spermogonia in twelve species of Collema. In tliis 
genus he finds them always intmersed in the tissue of the thallus and 
more or less ineonspieuous ttnless the thallus is moistened. They are 
brownish or yellowish and either distributed on the surface of the thallus 
or on its margin. In Collema pulposum Acli. he described the edge of 
the thallus as well as the exciple of the apothecium as “sometimes studded 
over with conspicuous ragged, deep perforations, which are the ostioles 
of old sperntogones”. In Collema crispum Ach. the spermogones are 
described as in C. pulposum. In C. pulposum var. tenax, the spermogonia 
are tubercles of the same eolor as the thallus and scattered upon the 
edges of the lobes. 
Nylander (71) made nttich the sante distinction between stylospores 
and spermatia. According to tliis author, the stylospores differ from 
the spermatia in the greater tliiekness of the “basidia”, which are always 
simple, in tlieir fewer number, larger size, oily content, and power of 
germination. Nylander found in the structure of the sperniogonium, 
and in the size and shape of the spermatia, characters which served liint 
as a basis for Classification. 
Tulasne’s distinction between spermatia and stylospores of conidia 
had remained without being seriottsly questioned for a number of years. 
The subject was again taken up by Cornu (21) and his studies led him 
to conelude quite differently front Tulasne. By using a nutritive solution 
probably similar to that which surrounds the spermatia in tlieir natural 
substratuni, or in some cases by using only water, Cornu succeeded in 
germinating the spermatia of a considerable number of ascomycetes. 
His experiments on the lichens Borrera ciliaris and Parmelia acetabulum 
gave only negative results. To explain this failure, Cornu points out 
that there is an added difficulty in the study of liehen spermatia in that 
in other ascomycetes the spermogonia disappear after the spermatia are 
