109 
10. Chantransia virgatula (Harv.) Thur. emend. 
I have for a long time been in doubt whether the forms mentioned under this 
species ought to be regarded as distinct species or as forms of one species. It is 
easy to point out within this group of forms some fairly different types, and I 
tried at first to carry out the first alternative, but I then repeatedly met individuals 
which might apparently with equal right be referred to one or other of the pre- 
sumed species. As the delimitation of the species seemed not to be facilitated by 
the establishment of new species embracing the intermediate forms nor by divi- 
sion otherwise of the forms, I have ended by referring them all to one species. My 
observations have led me to the view, that this species is able to take various 
forms under different conditions. I dare not deny that any form referred to it may 
possibly prove on closer examination to be a distinct species, but as I have not 
been able to draw the limits, I have judged it best to keep them together. 
The species was first described by Harvey in 1833 and figured by the same 
author in Phyc. Brit. pl. 313 (1851), where it was represented with tetrasporangia, 
showing even partly tetrahedral division. The last must at all events be wrong, 
and it has also been supposed by Tuurer (Le Joris Liste p. 104) and later authors 
that the statement of tetrasporangia was founded on some mistake. It was then 
generally accepted, that this species, as well as all other species of Chantransia, 
had only monosporangia, until Schmitz and HAUPTFLEISCH briefly mentioned 
(1896 p.331) that tetrasporangia may occur together with the monosporangia in Ch. 
secundata. Later the same was observed in Ch. virgatula by BorGESEN and Kuckuck 
(BORGESEN 1902 p. 351), and the observation of Schmitz was confirmed by BORGESEN 
(1. c. p. 350) and Kyrın (1907) for Ch. secundata. I have also found tetrasporangia 
in the latter but in particular in a form coming near to the typical Ch. virgatula 
(f. tetrica). 
As will be shown below, the forms referred to this species differ principally 
in the nature and intensity of the ramification, the length of the cells and the 
number of spores in the sporangia; in other respects they are quite alike. Thus, 
the structure of the cells is the same. The chromatophore contains an axile pyre- 
noid situated in the upper part of the cell and gives off a number of branches 
downwards and upwards; under the chromatophore a nucleus is visible. The ger- 
mination takes place in the same manner in all the forms, the germinating spore 
dividing by excentric walls into an inner triangular and three peripheral cells, 
without changing the orbicular outline (figs. 37 C, 38 A—C, 39 C—D, 40 E, 41 A), 
(comp. Murray and BARTON (1891) p. 212 pl. 37 fig. 5; Kyrın (1907) fig. 24). Some 
small differences may sometimes occur (fig. 40 F), but the greater part of the spores 
germinate as described. The orbicular outline of the basal disc may sometimes 
hold out for a long time, in other cases some of the peripheral cells grow out to 
creeping filaments at an early period (figs. 39, 40). The number of erect filaments 
given off from the basal disc is usually low; the first is produced by the central 
triangular cell, the following from the neighbouring cells. 
