UTILIZATION OF ELM. 7 
2. Pores of early wood in a single tangential row. 
a. Pores of early wood comparatively large, forming a continuous row; 
bands of small pores numerous, usually about as wide as the inter- 
vening bands of dense tissue. Wood moderately hard and heavy. 
White Elm, Ulmus americana. 
b. Pores of early wood minute, individual pores scarcely visible to the 
unaided eye, often rather widely separated; bands of small pores not 
so numerous as in white elm, narrower than the intervening bands 
of dense tissue (except in narrow rings). W T ood very hard, heavy, 
dense Cork or Rock Elm, Ulmus racemosa. 
SUPPLY AND DEMAND. 
RANGE AND SIZE OF SPECIES. 
The botanical range of white elm includes nearly all of the region 
east of the Rocky Mountains (fig. 1). The area of principal com- 
Fig. 1.— Distribution of white elm (Ulmus americana). 
mercial importance, however, is southern New England, the Great 
Lakes States, and the southern Mississippi Valley. White elm is 
the largest of the elms, frequently attaining a height of from 100 
to 120 feet, with a buttressed trunk from 6 to 10 feet in diameter. 
The range of slippery elm (fig. 2) is nearly as great as that of white 
elm and includes practically the same territory. Slippery elm is not 
