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, R/iamnus, &c. 



FIG. 9. Transverse section of the wood of Acer pseudo-plat anus, 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 rays 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 



