July 8, 1910] 



SCIENCE 



59 



figures. Unfortunately Mr. Distant, in de- 

 scribing tlie new genera and species, scarcely 

 ever makes any comparisons with their allies. 

 The same criticism may be made of many 

 of Mr. Fletcher's descriptions of Seychelles 

 Lepidoptera, and of numerous other recent 

 publications of new species of insects. If 

 the species or genera described have been as- 

 certained to be new, they must have been 

 ■compared with their relatives, and there seems 

 to be no excuse for omitting information on 

 this point, which would be of so much service 

 to subsequent workers. Mr. Fletcher's long 

 and elaborate account of the Lepidoptera 

 brings out a number of interesting facts. For 

 the Seychelles proper he enumerates 120 spe- 

 cies, of which only 17 appear to be precinctive. 

 Putting aside the widely-spread forms, the 

 specially Indian element is very small; the 

 African is distinctly greater. Among the 

 butterflies, only a single species {Parnara 

 morella} is peculiar to the Seychelles; two 

 others are confined to Aldabra and the Sey- 

 •chelles. In a brief account of the Lepidoptera 

 of the Chagos Archipelago 26 species are 

 ■enumerated, three being precinctive. One 

 butterfly (Junonia vellida) is Australian, and 

 is supposed to have arrived by way of Christ- 

 mas Island. 



T. D. A. COCKERELL 

 THE GEOGRAPHY OF FERN'S 



The venerable pteridologist, Christ, in the 

 ■course of a long and exhaustive study has 

 accumulated a wealth of fern information not 

 ■directly usable in taxonomic publications, 

 ■which he has lately brought together in a 

 -separate volume.' His treatment comprises 

 ■separate analyses of environmental and geo- 

 ^'raphic considerations. 



Though of an ancient line of descent with a 

 fairly large persistence of Tertiary or earlier 

 types, and comprising a rather insignificant 

 fraction (considerably less than 10,000 spe- 

 ■cies) of the present vascular flora of the world, 

 the ferns are found to follow the same distri- 



^ H. Christ, " Die Geographie der Fame," Jena, 

 Verlag von Gustav Fischer, 1910, 8vo, pp. 357, 

 %s. 130, maps 3. Price 12 Marks. 



butional laws as the more modern and now 

 dominant seed plants and to show similar 

 endemic centers. Though on the one hand 

 tolerant of extreme precipitation, and on the 

 other presenting some of the most marked 

 examples of serophytic dormancy, they appear 

 to have been in the main less pliable than the 

 seed plants. Few grow where the annual rain- 

 fall is less than 25 inches and their lateral and 

 vertical distribution in general agrees with 

 that of forests, their greatest occurrence being 

 coincident with that of the tropical forests 

 under a rainfall of 80 inches or more per year ; 

 one only is aquatic, and only two or three are 

 halophytes. In adaptive form they ring nearly 

 all the changes from minute epiphytic or ter- 

 restrial herbs to lianas, climbers and trees; 

 and slime protection, nectar secretion, myr- 

 mecophily, food and water storage and numer- 

 ous and varied provisions against drought, 

 parallel those of the spermatophytes. The 

 chief areas differentiated by their floras are: 

 the cool-temperate northern forest regions, the 

 Mediterranean region, China-Japan, Malaya, 

 Australia-New Zealand, tropical Africa, south 

 Africa, the Mexican table-land, tropical Amer- 

 ica, the south Brazilian campos, the Andes, 

 and the south-Chilean region. 



Though sometimes separated from the ex- 

 planatory text, the many original half-tone 

 illustrations of form and habit add much to 

 the attractiveness and usefulness of what must 

 be regarded as at once an unusual and a 

 valuable contribution to botanical literature — 

 the richness of which in specific information 

 is indicated by a three-column index of over 

 fourteen pages, devoted to the forms mentioned 



in the text. 



W. T. 



An Outline of Individual Study. By G. E. 



Partridge, Ph.D. New York, Sturgis & 



Walton. 1910. Pp. v + 240. 



This book is intended as a guide for those 

 who wish to engage in the study of individ- 

 uals. The author believes that it will be of 

 value to superintendents and teachers and that 

 such study might well supplement if not take 

 the place of general psychology in normal 

 schools. 



