750 



SCIENCE 



[N. S. Vol. XL. No. 1038 



but that is, perhaps, too far afield for this work, 

 and a companion to it upon field botany may 

 follow. 



Concerning the fourteen phyla it is evident 

 that number of species is no criterion as, for 

 example, the calamorphyta with its twenty- 

 four existing species, in a single genus of 

 insignificant plants, stands in the same grade 

 of groups with anthophyta with its 132,000 

 present-day species. The authors state that 

 "philosophically a phylum originates with 

 the incoming of a new idea. Stated structur- 

 ally, it has its beginning with the development 

 of a dominant morphological peculiarity. 

 Stated taxonomically its initial point is indi- 

 cated by the appearance of a new character." 

 So long as the " new character " dominates 

 the phylum remains, but later " ideas " may be 

 expressed, and when they become dominant new 

 phyla arise successively, and thus the phylo- 

 genetic tree is built up. It is evident that 

 there might be some difficulty in securing the 

 weights of new ideas in the scale pan of 

 phylogeny, determine t(he dominance of a 

 " morphological peculiarity " and the appear- 

 ance in time of a " new character " — all of 

 phylum grade, and therefore so long as the 

 personal equation plays its role the last shift 

 in the phylogenetic scheme is not yet made. 



The " Key to the Phyla of Plants " follows 

 directly upon the fourteen phylum chapters, 

 occupies fifty pages, brings the classification 

 down through classes, orders to families and 

 under these last 683 groups illustrative genera 

 are named. This feature of the book is closed 

 with reproductions of wall charts showing in 

 one the relationship of the phyla and in the 

 other those of the orders in the anthophyta. 

 These charts will be of great help in genetics 

 and perhaps the publishers may be induced to 

 issue them in large size for classrooms. It is 

 a pleasant thought that these charts, when 

 reduced to page size, suggest at first glance the 

 forms of certain species of algse and fungi. 



The early chapters remind one of the first 

 edition, particularly those upon " Tissues " 

 and " Tissue Systems." More space for 

 greater elaboration seems advisable here, and 

 the single chapter upon physiology needs ex- 



panding to three upon nutrition, growth and 

 reproduction, respectively, with possibly one 

 upon pathology — a subject that nowadays can 

 not be adequately treated in four small pages. 



Chapter V. " The Chemistry of the Plant " 

 is an assemblage of the plant constituents with 

 their formulse and occurrence. These pages do 

 not admit of use as either text or laboratory 

 studies, and would make an appropriate ap- 

 pendix, possibly associated with a similar 

 grouping of phytophysical facts and principles. 



Twenty-nine pages of index " speak vol- 

 umes " for the book. 



It is a matter of regret that in a text-book 

 where evolution is the fundamental thought 

 the subject of species-making is not presented 

 somewhat fully and even historically in out- 

 line. Under the topic " Variations " both 

 " natural selection " and " Mendelism " are 

 touched upon and " mutations " barely men- 

 tioned. It is judged that the authors are 

 essentially Darwinians who strengthen their 

 book by frankly stating their ignorance of the 

 way " inherited variations " arise. They are 

 equally wise with their " we do not know " in 

 other places in the text. 



As a general criticism, previously hinted, 

 the book seems too small for its contents. The 

 tendency to list instead of to elaborate is felt, 

 due doubtless to a fixed limit of space set by 

 the series of which it forms a unit. The 

 authors have done their work admirably under 

 the pressure, and it is regrettable that the 

 publishers are sometimes at fault. Fanciful 

 colored pictures that inflame the imagination 

 are not asked for, but clear photo- and line- 

 engravings that supplement the text are de- 

 manded. Many of the illustrations are too 

 small and " inky " ; for example, those under 

 physiology, and give the pages a " pinched " 

 appearance. Even the full-page phylum charts 

 require a reading glass, in parts, for their use. 

 The proof-reader fails at times as in uniform- 

 ity of type for botanical names of plants (e. g., 

 p. 53). 



Botanical teachers and taxonomists and 

 paleobotanists as well, can not but feel deeply 

 thankful for the appearance of this new text- 

 book differing from others in its point of view 



