NOTES AND COMMENT 



An account of the use and sources of lignum vitae has been con- 

 tributed to The Scientific American by Prof. Samuel J. Record, of 

 Yale Forest School. This tropical tree received its name in the days 

 of the Spanish explorers, when its wood was erroneously supposed to 

 possess great medicinal virtue. At present the use of this very durable 

 and highly cross-grained wood is almost confined to the lining of shaft 

 bearings in steamships. No other material is found so satisfactory 

 for use in the last or sternmost bearings of the propellor shaft, where 

 the presence of salt water and the impossibility of lubrication would 

 make metal bearings impossible. There is still an adequate supply 

 of true lignum vitae (Guaiacum), although much of it is difficult of 

 access, and the same use is less satisfactorily served by Maracaibo 

 lignum vitae (Bulnesia), and by the Central American yellow guayacan 

 (Tabebuia), which was used for shaft bearings by the Emergency Fleet 

 Corporation during the war. 



Prof. John W. Harshberger, of the University of Pennsylvania, has 

 contributed an illustrated paper on the Alpme Fell-fields of Eastern 

 North America to the April issue of the Geographical Review. The 

 nature of these unforested, rocky areas in Greenland, Iceland and the 

 mountains of Europe and South America is discussed and a more de- 

 tailed description given of the fell-fields near the summit of Mt. Wash- 

 ington. Professor Harshberger holds that differences in the colloquial 

 names applied to prominent plant formations of America and Europe 

 have obscured their actual features of similarity, which can be ascer- 

 tained only after adequate descriptions have been published. 



Tt is stated by the daily papers that the Michigan Legislature has 

 authorized the use of a portion of the proceeds of a recent issue of 

 highway bonds for the planting of nut-bearing shade trees along the 

 roadsides of that state. Federal and county appropriations are also 

 likely to be obtained for this purpose. The three-fold benefits to be 

 secured from such a plan will doubtless commend it to other states. 



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THE PLANT WORLD. VOL. 22, NO. 4 



