August 14, 1908] 



SCIENCE 



213 



mental growth. Professor Swift, if I uuder- 

 stand him, accepts neither of these conclu- 

 sions, but he does not clearly deny them. 

 Nor does he make clear the very complicated 

 states of affairs of which the data given are 

 but one aspect. 



Concerning some of the conclusions which 

 Professor Swift does definitely accept (such 

 as: "Every young child must he regarded as 

 a potential genius," "It is doubtful whether 

 in three fourths of the cases criminal tend- 

 encies are anything else than a convenient 

 name ivith which to cover our social sins and 

 failures in education" "Progress [in the 

 course of practise] is never steady, hut always 

 hy leaps"), it must be noted that other intel- 

 ligent investigators possessed of the same 

 facts as the author would still not proceed 

 to his conclusions. The ambiguities of units 

 of mental measurement and the complexities 

 of selective influences play too large a role 

 in almost all our studies of human nature to 

 leave any one's work exempt from revision 

 and amendment. 



The book is interesting throughout, partly 

 because of the selection of topics and partly 

 because the author possesses the admirable 

 quality of writing to produce reactions in 

 others rather than to express his own thoughts. 

 The lack of an index should be remedied, 

 especially since the book is a collection of 

 essays whose separate titles can not at all 

 adequately describe their contents. 



Edward L. Thorndike 



Teacheks College, 

 Columbia Univeesity 



BOTANICAL ^WTES 

 RECENT SYSTEMATIC PUBLICATIONS 



The fourth part of Dr. A. J. Grout's 

 "Mosses with Hand-lens and Microscope" 

 appeared late in April of the present year. 

 It covers pages 247 to 318, and includes the 

 completion of the family Leskeaceae and about 

 half of the Hypnaceae. Twenty full-page 

 plates, mostly from the Bryologia Europaea 

 and Sullivant's Icones Muscorum, and thirty- 

 two cuts serve to illustrate the text. The an- 

 nouncement is made that the closing part 



(V.) will be issued some time next year (1909). 

 This closing part will complete the family 

 Hypnaceae, and include analytical keys to 

 sterile mosses, a list of errata, and a complete 

 index. When the whole work is finished it 

 will be a most useful addition to American 

 bryological literature, and an indispensable 

 aid to the beginner in the study of mosses. 

 The fine quality of paper and the clear type 

 and good presswork add much to the pleasure 

 one experiences in using the book. 



The problem of introducing the student to 

 the work of identifying the plants about him 

 is one which has puzzled botanical teachers 

 not a little, especially since the introduction 

 of laboratory studies has left little time for 

 the old-fashioned preparation by the study of 

 some such text-book as the old Gray's "Les- 

 sons" of our boyhood days. When this was 

 used the pupil had nothing to do but to get 

 ready for field work and the "classification" 

 of flowering plants. That was all there was 

 in botany. We had to run over the book in 

 order to know how to "classify" the spring 

 flowers when they appeared. We had to know 

 the meaning of such words as cordate, ovate, 

 spatulate, serrate, dentate, crenate, sepal, petal, 

 introrse, extrorse, hypogynous, epigynous, de- 

 hiscent, indehiscent, orthotropous, anatropous, 

 albuminous, esalbuminous, etc., for these were 

 in constant use in the keys to the families and 

 genera, and the descriptions of all botanical 

 groups from divisions and classes to species 

 and varieties. Thus long ago ; but now-a-days 

 after a longer or shorter course in laboratory 

 botany where he has learned something of the 

 evolution of the higher plants from the lower, 

 he is sent to the fields with no previous in- 

 struction in the terminology of plant struc- 

 tures. He is told to " dig out " the identifi- 

 cations of the plants he finds by the aid of 

 some manual of systematic botany. And it 

 must be confessed, it is often pretty hard dig- 

 ging. The keys and descriptions are so tech- 

 nical as to be difiicult of understanding, while 

 the number of species described in the manual 

 is so great as to bewilder and confuse the 

 would-be botanist. Hence has arisen the de- 

 mand for simple, local floras. By the use of 

 non-technical descriptions it has been found 



