On THE PITHOPHORACE. 43 
theirs, is clearly evident.1) As to my opinions on the systematization 
of the: lower plants, they accord so essentially with those pronounced 
by Professor Au. Braun on this head in his lecture »Ueber die neueren 
Eintheilungsversuche der Thallophyten» *), that I may here content myself 
with referring to that work. 
VI. ON THE SPECIFIC CHARACTERS. 
A glance at the figures which accompany this essay may be 
enough to convince us that all the Pithophoracew as yet known are very 
nearly related to each other. They are in fact so nearly related, that 
they must without question form only one genus. At first it may even 
seem dubious whether it is possible to distinguish any well limited and 
»good» species; but a nearer study of the forms of Pithophoracew 
removes this doubt completely. By a close comparing investigation we 
find that the different forms, however great the resemblance may be as 
to their general habitus, are, however, distinguished by a not inconsi- 
derable number of peculiar characters, taken no less from the nature of 
the reproductive system than from that of the vegetative. I will now 
try to show what those characters, which may be used for the distin- 
euishing of species, are. 
As to the vegetative system, it furnishes good characters by the 
differences in the ramification of the cauloid. In two species branches 
exist only of one degree, in others sometimes of one and sometimes of 
two, and in others of three degrees.*) (See more in extenso on this 
1) If we consider what place in the system Pithophoracee would obtain if the 
Cohn-Sachsian principles were applied, it would be a very isolated one. As they 
have neither zygospores, basidiospores, ascospores, tetraspores, zoospores, oospores or 
carpospores, they would have no place either in Cohn’s groups of Zygosporee, Basi- 
diosporce, Ascosporee, Titrasporce, Zoosporce, Oosporeé, nor in Sachs’ classes of 
Zygosporee, Oosporee, Carposporce. As it would no more seem fit to range them 
among the Schizosporee Cohn or the Protophyte Sachs, nothing would remain but 
ae a perfectly new class for them. 
2) Held in Gesellschaft naturforschender Freunde zu Berlin d. 19 Jan. 1875 
and reported in Bot. Zeit. 1875, pages 208—211. 
3) Among the species of which I had before a more complete knowledge there 
is only one, P. Roettleri (Roth) nob., which has branches of three degrees. In P. 
ocdogonia (Mont.) nob., of which I have not received material for examination till 
later (during the printing of this essay), another is found. In one specimen of this 
species, represented pl. 6, fig. 4, I have seen’a branch of no less than the 4:th degree 
(marked 6+), though, it is true, feebly developed. 
