318 APPENDIX IV 



and those in whicli they are not so distinct, such as Hawthorn, Pyms, 

 Birch, Box, Willows, Poplars, etc. The Maples are hard woods, varying in 

 colour, in the regularity of their rings, and in the presence or absence of pith- 

 flecks : they seldom have a distinct heart ; and their pith-rays have a satin- 

 like lustre which imparts a distinctive shine to the whole surface. The 

 Sycamore {Acer Pseudopldtamcs), (Plate XXXII.), has a moderately hard and 

 heavy, white wood, with regularly circular annual rings defined by a narrow 

 line of autumn-wood. Its pith-rays are straight, tapering out at both ends, 

 white and lustrous. Its pores are numerous, but not crowded, and are often 

 grouped two to five together. 



The Hollies, represented (Plate XXXIII.) here by Ilex opdca, an American 

 species, have greenish-white, white, or grey wood, generally hard, and fine, 

 and close in grain. The rings, though often indistinct, are mostly regularly 

 circular, and are marked by a sHght pore-ring. The pith-rays are straight, 

 sometimes tapering, not markedly satiny, and far more conspicuous in longi- 

 tudinal sections than in transverse ones. The pores are mostly in long radial 

 rows. 



The wood of Idriodendron tuUpifera, the TuHp-tree (Plate XXXIV.), and 

 that of the closely aUied American Cucumber -tree, Magnolia acuminata, dis- 

 tinguished by broader sapwood, come to market as " Canary Whitewood." 

 It is white, canary-yellow, or grey, and, being a quick-growing species, has 

 often wide rings, so that the confusion of its wood with that of the Poplars 

 was excusable. A slight diminution in the number and size of its pores 

 characterizes the narrow zone of autumn -wood by which the rings are defined, 

 The rings are for the most part evenly circular. The pith-rays are numerous, 

 straight, colourless, and hardly visible to the naked eye ; and the pores are 

 numerous, crowding almost all the space between the rays, and varying 

 sHghtly in size. 



Though not in any way systematically related to the MagnoUdcece or the 

 Linden, between which it stands in our classification, the wood of Liquid- 

 dmhar styraciflua, variously known as Bilsted, Sweet Gum, CaHfornian Red 

 Gum, Satin Walnut, and Hazel Pine (Plate XXXV. ), has many points of 

 structural resemblance to that of the former. Its wide rings are clearly 

 marked by a fine Hne of autumn-wood ; its numerous pith-rays are fine and 

 straight; and its numerous pores are nearly uniform in size, and crowded 

 throughout the spaces between the rays. Some of these pores contain the 

 hygroscopic gum or balsam, known as " styxax," which produces both warp- 

 ing and twisting of the wood. The soft tissue is represented by small isolated 

 patches. Satin Wahiut, when grown on high ground, is marked by dark- 

 brown or smoky false -rings. 



Tilia americdna, the Basswood (Plate XXXVI.), does not differ much from 

 our European Lindens. Its rings are not very clearly defined, and have a 

 wavy contour. Its pith-rays are numerous, but not equidistant, fine, straight, 

 and less lustrous than those of the Maples ; and its pores form a ring of variable 

 width in the spring-wood, and are also uniformly distributed, often three to six 

 together, but not crowded, in the rest of the ring. There are very narrow 



