XXX 



EBMARKS ON THE STEUCTUEE OF WOOD. 



The peculiar structure of the wood of Coniferous trees, Palms, and Bamboos, 

 is suflBciently explained at pages 502, 541, and 561. In this place it is intended 

 to draw attention to the character of the main classes of Dicotyledonous woods, 

 so far as they can be distinguished under the lens without the aid of a micro- 

 scope. The classification here suggested is not complete ; it only applies to 

 the trees mentioned under each class. Orders and genera with anomalous wood- 

 structure, and climbers, are not included. The object of these remarks is to 

 offer a few practical hiuts, which may induce Foresters and others, who have to 

 deal with Indian timbers, to examine the structure of the diiferent kinds. 



First Class. — Pores equal in size and uniformly distributed, sometimes a 

 narrow belt with few pores at the outer edge of the annual ring, or a narrow 

 belt with more numerous pores at its inner edge. 



A. Medullary rays narrow or fine, generally all of one width. 



1. Annual rings diatmat.—Suoni/mvs europcBUs, Zizyphus vulgaris, Acer 

 camipestre, A . dasycarpum, JEsculus, Schldchera trijv^a, Odina Wodier, Pyrus, 

 Mespilus, Cratcegus, Eriohotrya, Gareya arhorea (pores scanty, in oval groups 

 of 3-6, uniformly distributed, a narrow belt of darker wood at each ring), 

 Punica Oranatum, Cornus, Viburnum, Coffea, Diospyrus Lotus, Ligustrum 

 vulgare, GinnamomuTn Camphora (pores large, in radial lines), Elceagnuik 

 Buxtis, Betula, Salix (S. tetrasperwia, from Burma, however, has larger and 

 more numerous pores in the spring wood, and 8. caprea has a similar structure, 

 but less marked), Populus, Juglans regia. 



2. Annual rings more or less indistinct. — The division between this and the 

 first group is uncertain, for the wood of the same kind often has the annual 

 rings distinct when grown in dry places or at high elevations, while under other 

 circumstances the zones of annual growth cannot be distinguished. Bomhax 

 malaharicum (pores large, numerous), Gapparis aphyUa, Shorea rohusta, Melia 

 Azedarach, Mamgifera irulica, Terminalia tcmieihtosa, Conocarpus acuminata, 

 Eugenia Jambos, Lagerstrxmia parviflora (pores large, numerous whitish 

 wavy concentric bands, not annual rings), Nauclea cordifolia, N.' parmfolia 

 (pores fine, in radial lines between medullary rays), Olea europcea. 



B. Medullary rays of two classes, broad and narrow, the broad rays very 

 marked. 



1. Annual rings distinct. — DUlenia imdica, Ace/r pseudoplatanus, Negund/o, 

 Sta/phylea pinnata, Platanus orientalis, Alnus nepalensis, A. glutinosa, Fagus 

 sylvatica, Garpinus orientalis, and Betylus. 



2. Annual rings more or less indistinct. — To this section probably belong 

 several species of DUlenia and Carallia integerrima. 



