PERIODICAL LITERATURE 56? 



magnification. The ripple marks are nevertheless very fine and may 

 easily be overlooked, for there may be from 45 such lines or striations 

 per inch of length in some species to as many as 280 in others. These 

 ripple marks are often sufficiently characteristic to be used for identi- 

 fying the species. Nearly every wood showing 125 to 190 lines per 

 inch belongs to the Leguminosae, which family contains the great 

 majority of the woods having this striation, and the investigated woods 

 of Zygophyllaceae have considerably more than 200, mostly 250. This 

 fact is of value in distinguishing true lignum vitae from its various 

 substitutes. 



Ordinarily the wood fibers are much longer than the vessel segments 

 or the height of the tiers. The fact that the fibers are so interlaced 

 prevents wood having this storied structure from being weak in the 

 planes of the tiers. 



The medullary rays are frequently also in horizontal layers. When 

 this is the case the rays occupy an intermediate position, the height of 

 the tiers (distance between the lines being considerably greater than 

 the height of the rays. Some rays, however, may cover two or three 

 stories in height especially in woods which have two sizes of rays, as in 

 Cercis. Where the rays are in perfect seriation, a cross section be- 

 tween two tiers may miss them completely, or may show rayless gaps 

 if the plane of section does not exactly parallel the plane of the ray 

 seriation. 



The storied arrangement occurring in the wood is also present in 

 the secondary phloem. 



Professor Record has painstakingly marked out a comprehensive 

 table giving the characteristics of all the elements in this respect, the 

 degree of visibility, and the number of tiers per inch for twenty-one 

 families and some 220 species of wood. 



H. D. T. 



"Storied or Tier-Like Structure of Certain Dicotyledonous Woods." Samuel 

 J. Record (Contribution No. 4 from Yale School of Forestry). Bull. Torry 

 Bot. Club, July. 1919, pp. 253-273. 



De Lapasse has written at length on the results 

 Tapping of tapping Corsican pine in Corsica, and also on 



Corsican Pine the relative results of the shelterwood and selec- 

 tion systems. Tapping of this species was prac- 

 ticed from 185G to 1872, and the production was greatest between 1862 

 and 1867 because of the demand for turpentine during the American 



