May 17, 1895.] 



SCIENCE. 



551 



their ' Natiirliche Pflanzeufamilieu ' will ap- 

 peal to many students as iu some respects 

 more philosophical, all the suggestions con- 

 tained in this book must be regarded as 

 very valuable. 



Plants are here divided into five gi-eat di- 

 visions : (1) Thallophyta ; (2) Muscinea' ; 

 (3) Pteridophyta ; (-t) Gymnospermse ; (.5) 

 Angiospermie, We note in this a departure 

 from some recent views where the divisions 

 2, 3 and 4 have been grouped under the 

 primary division Archegoniat;e, and from 

 others where the divisions 4 and 5 have been 

 grouped as Spermatophyta, 



Dr, "Warming does not discuss the rela- 

 tive value of these diflerent views, content- 

 ing himself with alluding to them. AVe 

 may note that the disadvantage of i-ecog- 

 nizing the Archegoniata; as above circum- 

 scribed is found iu the fact that the female 

 organs of the Augiosperms are also arche- 

 gones. It must be admitted that the group- 

 ing here maintained has many points in its 

 fevor, but it is our opinion that the term 

 ' sub-kingdom ' is more explicit for the 

 primary groups than ' division.' 



The Thallophyta are tli^•ided into ' sub- 

 divisions' : (a) Myxomycetes, (b) Algse, (c) 

 Fungi. It is said of the Myxomycetes that 

 " they occupy quite an isolated position in 

 the vegetable kingdom, and are perhaps the 

 most nearly related to the group of Rhizo- 

 pods in the animal kingdom.'' The Bacteria 

 are treated, uuphilosophically,it would seem 

 to us, as a family of Alga-, being grouped 

 with the Schizophycete under the class Schi- 

 zophyta. The treatment of the higher Alga' 

 and Fungi is not essentially different from 

 that of other recent authors. (It should be 

 remarked that the arrangement and descrip- 

 tion of the Thallophytes is largely contri- 

 buted by Dr. E. Knoblauch.) The Fungi 

 imperfecti are placed at the end of the sub- 

 division, and the only gi'oups admitted to 

 this category are the Saccharomyces-forms, 

 the Oidium-forms and Mycorhiza. Lichens 



are discussed under Ascomycetes and Basi- 

 diomycetes. 



The Muscinete are treated as (1) Hepaticae 

 and (2) Musci frondosi. Neither in these 

 nor in the Pteridophyta do we find any 

 views very different from those of other re- 

 cent authors. In the Gymnosperms we 

 find the three classes, Cycadea?, Coniferae 

 and Gnetea?, maintained ; the Coniferie are 

 distinctly separated into two families, Tax- 

 oideffi and Pinoideie, which is a suggestion 

 of much importance. 



Under the Angiospermse we find a discus- 

 sion of the systematic value of the primary 

 group Chalazogams, recently suggested by 

 Treub. It will be remembered that Treub 

 found that in the curious genus Casuarina 

 the pollen-tube entered the ovule near the 

 chalaza, and on this character proposed to 

 divide the Ajigiosperms into Chalazogames 

 and Porogames, Camarina being the only 

 genus known to him that would fall into 

 his first group. Dr. "Warming concludes, 

 from the more recent observations of Na- 

 waschin and Miss Benson, which indicate 

 the similar entrance of the pollen-tube in 

 Betula, Alniis, Corylus and Cai-pinn^, that 

 our knowledge of this phenomenon is as yet 

 too meagre to warrant us in maintaining 

 the views of Treub, and so he adopts the 

 usual grouj)ing into Monocotyledones and 

 Dicotyledones. His primary grouping of 

 the Monocotyledones is as follows : ( 1 ) He- 

 lobiese, Juncaginacea' being taken as the 

 lowest type ; (2) Glumiflone, in which he 

 includes the Juncace;e, a position which we 

 do not believe can be satisfactorilly main- 

 tained ; (3) Spadiciflorse ; (4) Enantio- 

 blasta; ; (5) Liliiflor.Te ; (6) Scitamineteand 

 ( 7 ) Gj'nancb-ie. It will be obsei-\'('d that in 

 this arrangement he diffei-s considerably in 

 detail fi"om that of Eichler and Engler and 

 Pi-antl. The primary division of the An- 

 giosperma; is into (1) Choripetahe, begin- 

 ning with Salicaceae and ending with Hys- 

 terophyta (parasites such as the Lorantha- 



