78 
Notes on Recent Literature. 
NOTES ON RECENT LITERATURE. 
Professor Wille on the Classification of the 
Green Algd. 
“Conjugated: und Chlorophyced,” von N. Wille. Nachtrage 
zu Teil. I. Abt. 2, of Engler and Prantl’s Pflanzenfamilien. 
I T is now twenty years since Wille’s classification of the Conju¬ 
gate and Chlorophycee was published in Engler and PrantFs 
Pjlanzenfamilien. During these twenty years the list of the genera 
included in the two groups has grown to nearly double its former 
size, and it is therefore not surprising that, with so many new 
forms to be accommodated, and with the more complete knowledge 
of other genera which is now at our disposal, some considerable 
modifications of the earlier system have been introduced. Wille, 
however, finds himself by no means in agreement with the “complete 
transformations of the system ” which are characteristic of the 
attitude adopted in some of the more recent publications upon this 
subject, 1 and in his treatment of the Conjugate and Chlorophyceae 
in the recently published Nachtrage, he retains an arrangement 
which in respect of certain very fundamental points does not differ 
very greatly from that which he used in his earlier work. 
Having remarked on the general agreement that a natural 
system must, as far as possible, be arranged phylogenetically, Wille 
proceeds to point out that there are two methods of constructing a 
system of classification ; “ nach der einen stellt man zuerst 
doktrinar durchgreifende Merkmale auf, um die grosseren systema- 
tischen Einheiten zu trennen, und die kleineren systematischen 
Einheiten werden dann spater, wie sie sich am besten angliedern, 
unter die hoheren eingeordnet. Diese methode, die auch C. Linne bei 
seinem kiinstlichen Systeme verwendet wurde, ist sehr einfach und 
bekannt, gibt aber leider nicht ein phylogenetisches und naturliches 
System, sondern ein durchaus kunstliches, so, wenn bei den hoheren 
Pflanzen die Staubgefiisse oder bei den Algen die Cilien als Haupt- 
merkmale verwendet werden.” 
Having coupled the system in which weight is attached to the 
characters of the zoospores of the Algte with the artificial system 
of Linnaeus, it is not surprising to find that Wille does not accept 
the former. But we demur strongly to the presentation of such a 
' See, for instance :— 
Blackman and Tansley. “ A Revision of the Classification of the 
Green Algae.” New Phytologist, Vol. I., 1902. 
G. S. West. “ British Freshwater Algae ” (especially the section 
entitled “ I’hylogeuy,” pp. 21-33). Cambridge University 
Press, 1904. 
F. Oltmanns. “ Morphologic und Biologic der Algen.” Jena, 
Gustav Fischer, 1904. 
The above authors give references to the literature of the more detailed 
work upon which the modifications introduced into the system have been 
mainly founded. 
