232 The Plant World. 



work of Zopf, * seems to have proved that these tests are of some 

 auxiliary value in the detent. ination of lichens. 



One can not pass minutely upon the accuracy and efficiency 

 of keys without subjecting them, to the test of use. This re- 

 mains to be done by those who use the manual, but the keys ap- 

 pear to be excellent. The failure to make good keys is one of 

 the shortcomings of lichenists, and the author has wisely gone 

 through the drudgery of preparing them, thus making his manual 

 easily workable. 



Dr. Herre's manual is a valuable contribution to American 

 botany and will fill a long-felt need among botanists of the Pa- 

 cific slope. It is to be hoped that the author will extend his stud- 

 ies and give us a m.anual of lichens of the whole western portion 

 of North Am,erica. 



Miami University, 

 Oxford, Ohio. 



NOTES AND COMMENT. 



Suit has been brought by growers of citrus fruits in the vi- 

 cinity of Colton, California, against a cement factory, the dust 

 from which has been deposited upon the leaves of orange and 

 lemon trees in the neighborhood, apparently greatly to their 

 detriment. Botanical testimony has been taken at length and 

 forms an interesting chapter. Professor Peirce of Stanford and 

 Mr. S. B. Parish of San Bernardino, were summoned to give ex- 

 pert testimony, and have promised at the proper time to present 

 in The Plant World the results of their observations and ex- 

 periments. 



A notable and most useful contribution to the literature of 

 scientific pedagogy is again presented to botanical teachers in a 

 new and extended edition of "The Teaching Botanist," by Pro- 

 fessor W. F. Ganong. It should find a place in the working li- 

 brary not only of botanical teachers but of teachers of all sub- 

 jects who are interested in the developm,ent of pedagogy as a 

 science and at the same time as a practical m.atter, of which at 

 present many who are practicing the art have need that some 



*Zopf, W. Die Flechtenstoffe. I-XI. 1-4S0 f. 1-71. Jena, Gustav Fischer, 1907. 



I 



