T1IE MYXOGAS'f RES. 
Ill 
Monograph Mr. Massee has dispensed with this primary division, 
according to the colour of the spores, and proposes an arrange- 
ment, in harmony with his ideas of the relationship between the 
several orders, which may be represented as follows : — 
A. Wall of sporangium not incrusted with lime. 
1. Capillitium absent, or formed from the wall of the 
sporangium ..... Peritrich^e. 
Wall of spovangium not per- 
forated ..... Tubulince. 
Wall of sporangium perforated . Cribrarice. 
2. Capillitium originating from a central, usually elongated 
columella . Columellifer^e. 
Springing from every part of an elongated colu- 
mella ..... Stemonitce. 
Springing from the apical portion of a short or 
elongated columella . . Lamprodermce. 
3. Capillitium present, not springing from a colu- 
mella . . .... CALOTRICHEiE. 
Threads free, not anastomosing to form a net- 
work ..... Trichece. 
Threads attached by one end, with the free tips 
more or less branched, or combined to form an 
irregular network . . Arcyrice. 
B. Wall of sporangium with an external deposit of lime. Capil- 
litium present ...... Lithodermejs. 
Threads without lime . . . Didymece. 
Threads containing lime . . . Physarece. 
The value whicli is attached to this arrangement may be esti- 
mated from the following observations which occur in the 
Preface : — “ Notwithstanding the excellent work initiated by the 
late Professor de Bary, and continued by Brefeld, Cienkowski, 
Woronin, Zopf, and others, the life history of the majority of forms 
is still unknown ; hence all attempts at classification, as also the 
conception as to what constitutes a species, must be considered as 
tentative. When we are better acquainted with the main lines of 
development, and lines of variation, also the conditions of deter- 
mining these variations, it is certain that the main factor in the 
discrimination of species will not be a one-twelfth oil-immersion 
objective.” 
impressed with the feeling that, in the present condition of 
knowledge, the only safe guide to even a tentative arrangement, or 
a conception of the limits of species, is to be derived from the 
mature specimens contained in herbaria, our author has accepted 
these as his material, and reduced or constituted species, and 
genera, upon that basis. Hence he combines several, so-called, 
species in Cratenum and Badhamia, and interprets Arcyria as in- 
cluding Iiemiarcyria , and Stemonitis as embracing Comalricha. 
