KEY TO THE SPECIES 



1. Wiiite or nearly white woods (ecru, oatmeal colour, etc.) 2 

 la. Woods of pronounced colour . v' . .* 6 



2. Soft woods . . . . . . .. 3 



2a. Compact woods (from, say, the hardness of Spruce to 



that of Oak) . . . . . . .15 



3. Woods that are too soft for ordinary uses (except 



perhaps for floats) . . . . 4 4 



3a. Soft woods, but still fit for, say, drawer- bottoms . 5 



4. Rays (seen on a cross-section prepared with glass-paper) 



very fine .... Ricinodendron, page 70 

 4a. Rays rather coarse and readily visible 



Eriodendron, page 17 



5. Rays (on glass-papered cross-section) fine and appar- 



ently all of the same size ; they make a network with a 

 series of concentric lines which are nearly equally 

 fine . > . . . . Alstonia, page 66 



5a. Rays rather coarse, readily visible, and apparently of 

 very diverse thicknesses. No concentric lines visible 

 with lens .... Triplochiton, page 19 



6. Coloured woods Browns of various shades . . 7 

 6a. Colours other than brown (red, yellow, green, etc.) . 17 



7. Heavy brown woods ...... 8 



7 a. Comparatively light brown woods (say of the weight of 



Mahogany or less). (Medium weights are included 



in both categories) . . . . . . 24 



8. The pores (vessels) on cross-section are connected by 



long, light-coloured lines or bands . . 9 



Sa. The pores are isolated from one another or in short 



series only ........ 12 



9. The light-coloured concentric lines are very readily 



visible to the unaided eye . . . * . .10 



9a. The lines are very fine and may need the lens . . 43 



The Key being constructed on simple and popular lines adapted to 



the use of those who have but little knowledge of the structure of wood, 



is subject to the defect of too great generality, i.e. expressions such as 



" hard, soft, light, heavy," and the colours, which are very variable, must 



be allowed for. When in doubt as to which alternative to choose try first 



one and if it leads to an obvious error, try back and follow the second. 



Check by the descriptions. See notes, p. 87, and descriptions of plates. 



83 



