336 BOTANY. 



the lower to the higher Thallophytes. Thus the Zygosporeae, as a rule, 

 are single cells (Desmidiacece and Diatomacece), or rows of cells (Zygne- 

 macece, etc.), of simple structure ; the Oosporeae are generally single 

 cells of a complex structure (CcdoblasteoB), rows of differentiated cells 

 (CEdogoniecR), or even tissues, forming structures which have, in some 

 cases, a close approximation to stems and leaves (FucacecB) ; the Car- 

 posporeae are all multicellular ; the lower ones are made up of rows of 

 cells, which are generally united into a plant-body (sporocarp of Asco- 

 mycetes and Batddiomycetes), while in the higher ones there are tissues 

 which form stems and leaves (some Floridece and Characece). 



(3.) It can scarcely be doubted, then, that the three Thallophyte groups 

 Zygosporeae, Oosporese, and Carposporese, are as much entitled to rank as 

 Divisions as are those of the Cormophytes. The Protophyta constitute 

 a provisional group, but while it is very likely that many of the forms 

 now included in it may be placed elsewhere when they are better un- 

 derstood, it is extremely improbable that all will be thus disposed of ; 

 it seems more probable that the group may be preserved, very likely in 

 a modified form, as a sort of primary Division. 



(4.) The arrangement followed in this book may be made plainer by 

 the subjoined table. The Classes only (printed in SMALL CAPITALS) 

 are given, excepting where, for obvious reasons, it is necessary to 

 particularize more closely (Orders and genera in lower case). The 

 groups on the left are composed of chlorophyll-bearing plants, and 

 are regarded as the proper representatives of the Divisions. The 

 groups on the right hand (printed in italics) are composed of plants 

 which are parasitic or saprophytic, and which, as a consequence, show 

 more or less of degradation in their vegetative parts ; the absence of 

 chlorophyll here, as in the case of parasitic Phanerogams, is an accom- 

 paniment of structural changes in the vegetative parts of the plant, 

 which are always degradatioual in their nature. 



PROTOPHYTA. 

 MYXOMYCETKS. 



SCHIZOMYCKTBS. 



SaccJiaromycetes (?). 



CYANOPHYCE.K. 



ZYGOSPOREAE. 



Pandorina, etc. 



CONJUGATE. . . Mucwini. 



