S4 TlIK JUUK>AL OF JJOTAXT 



may he said that ]w lias succeeded in an admirable manner. The 

 volume contains an abundance of valuable information, most of which 

 has been sifted critically bv the author, and one can onl}^ praise with- 

 out reservation the clear and lucid &tyle and the able way in which the 

 facts are presented. 



The most obvious criticism is that the book is dominated too 

 largely by a sj^stematic atmosphere, making it indeed an excellent 

 introduction to a taxonomic study of the Algie, but decreasing its 

 value from the point of view of the student of comjiarative morphology 

 and phvlogeny. This is more apparent in the portion dealing witli 

 the Chloropbycese — in which the author, for stated reasons, adopts a 

 sectional treatment — than in tbe very excellent accounts of the 

 Myxophycejp, Peridineie, and Baeillariales. The Chlorophycese are 

 divided up into numerous short sections that make rather dull reading, 

 and obscure the many points of contact between the different sub- 

 divisions ; in our opinion a more collective treatment would have been 

 possible. The dominance of systematic considerations is also evidenced 

 by the inclusion of many minor details that are only relevant in taxo- 

 nomic work and are unnecessary in a book of this kind, since they 

 are to be found in the various monographs dealing with the different 

 subdivisions of the Alga?. 



To some extent morphological considerations have suffered at the 

 expense of systematic detail. As instances, we may mention that the 

 author gives no detailed account of the mode of development of the 

 daughter-colonies in the Volvoceai, that there is no reference at all to 

 Senn's.work on Ccelastnim and other Pi'otococcales. or to Eerthold's 

 work on the branching of various Algte, and that no mention is 

 made of the relatively permanent PalmcIIa -ahiges of certain species- 

 of Cltlamydomonas (e. g. C. Klcinii), which, must be regarded as of 

 imjtortance from the evolutionary ])oint of view. These are not the 

 only places in which a more comprehensive morphological treatment 

 would have been desirable ; but, on the other hand, there are many 

 sections which are quite admirable in the wide treatment thev have 

 received. As special instances we may quote the whole section on 

 Myxophyceai, the account of movements in ])iatoms, the sunnnary ou 

 methods of cidture of green Algje, and the section on Conjugata?. 



The general scheme of classification may be said to be in line 

 with modern views. The chief criticism to be made is the author's 

 inclusion of the Heterokonta? as a subdivision of the Chlorophyceae. 

 There is no evidence at all to show that the Flagellate ancestry of the 

 Heterokontai had anythmg in connnon with that of the Isokontse, and 

 the two groui)s aj^pear as sharply demareated from one another as any 

 of the grou])s of the Algie. As regards the other subdivisions of the 

 Cidorophyccie, the present writer regards the ado])tion of the names 

 Akontie and Stephanokontre as unfortunate, as tlu\v appear to lay 

 em))hasis on comjuiratively irrelevant characters. The Conjugatie are 

 by no means the only series of Green Algte in which motile elements 

 are lacking, and the nuniei-ous cilia of the zoos])ore of CEdogoniales are 

 })rol)ably to be related to the unusually large size of the zoospore, 

 Conjugat:e and G^dogoniales are better regarded as early offshoot* 

 fr* ni tlu' line of evohitiovi of the Isokonta*. 



