On the PiTHOPHOEACEiE. 43 



theirs, is clearly evident. ^) As to my opinions on the systematization 

 of the" lower plants, they accord so essentially with those pronounced 

 by Professor Al. Braun on this head in- his lecture »Ueber die neueren 

 Eintheilungsversuche der Thallophyteni> ^), that I may here content myself 

 with referring to that work. 



YI. ON THE SPECIFIC CHARACTERS. 



A glance at the figures which accompany this essay may be 

 enough to convince us that all the Pithophoracece 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 Avhether it is possible to distinguish any well limited and 

 »good» species; but a nearer study of the forms of Pithophoraceœ 

 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 sj^stem than from that of the vegetative. I will now 

 try to show what those characters, which may be used for the distin- 

 guishing of species, are. 



As to the vegetative system, it furnishes good characters by the 

 differences in the ramification of the caulo'id. 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 



') If we consider what place in the system Pitlioplioraceœ 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 Zygosporece, Basi- 

 diosporcce, Äscosporcce, Tctrasporcœ, Zoosporece, Oosporeœ, nor in Sachs' classes of 

 Zygosporece, Oosporeoß, Carposporece. As it would no more seem fit to range them 

 among the Schigosporece Cohn or the Frotopliytce Sachs, nothing would remain but 

 forming a perfectly new class for them. 



-) tield in Gesellschaft naturforschender Freunde su Berlin d. 19 Jan. 1875 

 and reported in Bot. Zeit. 1875, pages 208 — 211. 



^) Among the species of which I had before a more complete knowledge there 

 is only one, P. Rodtlerl (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 pi. 6, fig. 4, I have seen a branch of no less than the 4:th degree 

 (marked b'*), though, it is true, feebly developed. 



