II.] 



ITS PROPERTIES AND VARIETIES. 



25 



''annual ring," as in the alder, some willows and 

 poplars, &c. ; whereas in the chestnut and others they 

 are especially grouped at the inner side of the annual 

 zone {i.e. in the spring wood), and in some cases these 

 groupings are such as to form characteristic figures on 

 the transverse section, as in some oaks, Rhamnus, &c. 



Fig. g. — Transverse section of the wood of Acer pseudo-plataniis, selected to show 

 a type of timber common in Europe. The annual rings {a) are well-marked and 

 regular. The vessels are small and numerous, and scattered somewhat equally 

 over the whole breadth of the ring. _The medullary ravs are numerous, some 

 broad, some fine. Many European timbers (beech, hornbeam, lime, &c.) agree 

 with this type, except in detail. 



In the woodcuts (Figs. 7-10) I have given four 

 examples illustrating a few of the chief points here 

 adverted to. 



Passing over peculiar appearances due to the 

 distribution of the wood-parenchyma between the 



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