730 



SCIENCE. 



[N. S. Vol. XX. No. 517. 



cases, sometimes flat contradiction; but it is 

 safe to say tliat wherever Dr. Berger gives his 

 individual estimate of ancient wayfarers along 

 the road to knowledge, he has formed his opin- 

 ion from profound and conscientious study. 



The subject-matter of the work is arranged 

 chronologically according to authors, and as 

 the latter are generally occupied with a sur- 

 prising variety of topics, the historical con- 

 tinuity of certain lines of investigation be- 

 comes obscured by this method of presenta- 

 tion. A remedy for the defect would have 

 been to summarize in special chapters the 

 progress made in the study of particular phe- 

 nomena, such as the cosmical relations and 

 movements of the earth, volcanic activity, 

 tides, petrifactions, and the like. Tozer's 

 ' History of Ancient Geography ' is arranged 

 partially after this fashion, and is excellently 

 adapted, by the way, as an introduction to 

 the work above considered. 



0. E. Eastman. 



Harvard University. 



BOTANICAL NOTES. 

 THE STUDY OF PLANT DISEASES. 



An interesting pamphlet comes from the 

 antipodes under the title of ' Letters on the 

 Diseases of Plants,' by N. A. Cobb, of the 

 Department of Agriculture of New South 

 Wales. In somewhat over a hundred and 

 thirty pages the author has brought together 

 the substance of a great number of letters 

 written in reply to correspondents. He has 

 recast the matter so that the epistolary form 

 has been obliterated, and he has added a large 

 number of cuts in the text, and a dozen full- 

 page plates (some colored). Here in compact 

 form is to be found a great deal of informa- 

 tion in regard to many plants, stated in such 

 non-technical English as to render it easily 

 comprehensible by any intelligent person. 

 There is iirst a long discussion of ripe rot, 

 the fungus of which (Oloeosporium fructi- 

 genum) attacks the fruits of many different 

 plants. The results of many interesting ex- 

 periments are given in detail. Banana- scab 

 (Phoma sp.), stigmonose (due to insect punc- 

 tures), mouldy core of the apple (Penicel- 

 liiim, Mucor and others), quince rots, peach 



curl (Exoascus deformans), lemon and orange 

 diseases, diseases of the passion vine, potato 

 diseases, root-rots and timber rots, are among 

 the topics more or less fully treated in this 

 valuable publication. 



THE STUDY OF WOODS. 



Another book on the structure and uses of 

 the woods of commerce has made its appear- 

 ance in England under the title of ' The 

 Timbers of Commerce, and their Identifica- 

 tion.' It is from the hand of Herbert Stone, 

 F.L.S., and is issued by Rider & Son, of Lon- 

 don. It constitutes a neat volume of about 

 350 pages, and is beautifully illustrated with 

 186 photographs showing the grain of cross 

 and longitudinal sections of wood. There is a 

 general introductory chapter on the structure 

 of wood, and following this are the descrip- 

 tions of 247 different species. These descrip- 

 tions are very concise, a short paragraph (or 

 line) being given to each of the following 

 topics : Natural order, synonyms, sources of 

 supply, alternative names, physical characters, 

 grain, bark, uses, etc., authorities, color, pores, 

 rays, rings, soft tissue, pith, radial section and 

 tangential section. There is a good deal of 

 similarity between this book and the one pre- 

 pared by Professor Snow last year under the 

 title of ' The Principal Species of Wood,' and 

 noticed in these columns (Science, July 3, 

 1903), at the time of its appearance. The 

 American book takes up only about half as 

 many species as the English book, and its 

 descriptions are shorter, covering fewer points, 

 yet the much better arrangement and the 

 careful selection of species in the former 

 make it by far the more useful for the Amer- 

 ican student or artisan. 



COMPARISON OF EASTERN AND WESTERN FLORAS. 



The recent publication of two local floras 

 permits a comparison between an eastern roclty 

 area with one consisting of typical prairie con- 

 ditions. George G. Kennedy's ' Flora of Wil- 

 loughby, Vermont,' originally published in 

 Rhodora for June, 1904, takes up the plants of 

 Willoughby Mountain, Willoughby Lake and 

 the vicinity, in northern Vermont. The ele- 

 vation of the lake above the sea is 1,060 feet. 



