NOTES AND COMMENT 265 



those who are experimenting with the fertilizer treatment of crop 

 phmts in the field. It is suggested that the results of this correlated 

 set of researches may become a definite national contribution to knowl- 

 edge about one of the most important and fundamental of all physio- 

 logical problems. The cooperation was planned in war-time but it is 

 as much needed in time of peace as in time of war, and it is being pushed 

 forward with all reasonable haste. 



The Special Committee on Salt Requirements of Representative 

 Agricultural Plants has prepared a comprehensive plan for the pro- 

 ject, which may be obtained on request, and has made arrangements 

 for special lots of chemicals for this work, also for the special cork 

 supports needed in water cultures. Correspondence regarding this 

 project is earnestly requested, and all experimenters in this field are 

 asked to join in this national undertaking in one way or another. Cor- 

 respondence should be addressed to the Chairman of the Special Com- 

 mittee at the Laboratory of Plant Physiology of the Johns Hopkins 

 University, Baltimore, Md. 



Those who have given attention to the physical features of desert 

 regions, on account of the features themselves or of their relation to 

 the life of plants, animals or man, will be interested in the paper on 

 desert erosion and degradation recently published by Prof. W. H. 

 Hobbs (Annals of the Assn. of Amer. Geogr. vol. 7). His observations 

 were carried out in the Libyan Desert and have to do largely with 

 wind erosion by sand blast as a means of forming extensive depres- 

 sions. There is very little desert in North America to which Prof. 

 Hobbs' observations are directly applicable, and such attempts as he 

 makes to shape our interpretation of American desert features by 

 Libyan evidence are quite bootless. Even his statement that "The 

 greater vegetation of American as opposed to Old World deserts may 

 perhaps in part account for some difference in viewpoint" with respect 

 to the role of large-scale erosion by sand, does not seem to clear the air 

 for those canny ones who can tell when the cart is being put before 

 the horse. 



The Macmillan Company have published a second edition of W. S, 

 Harwood's New Creations in Plant Life. This is a popular — in fact a 

 somewhat cloying — account of the work of Luther Bm'bank, which 

 originally appeared in 1905 and has since been reprinted six times. 



