134 ANATOMY OF STEM, ROOT AND LEAF 



Cut longitudinal sections of the same ; examine and make sketches of the 



various i^arts. , , , . 



Ex. 66.— Cut and examine in a similar manner young one-year-old snoots 



of beech, oak, elm and ash trees. j , « 



Also- make and compare under a low power, transverse, radial and tan» 

 gential, longitudinal sections of pieces of the common timbers. 



In the following tables are given the characters of the common 

 timbers, which can be easily distinguished with the naked eye 

 and a pocket lens : — 



I.— TIMBER OF CONIFEROUS TREES. 



In these timbers the annual rings are very distinct (Fig. 63), the autumn- 

 wood is hard and dark-brown or reddish in colour, and sharply marked off 

 from the spring-wood, which is soft and much paler 

 in tint. Neither medullary rays nor porous rings 

 are visible. 



1. Heart-wood same colour as the Splint- wood. 



(a) Silver Fir (Abies pectinata D. C). 



(b) Common Spruce {Picea excelsa Lk.). 

 Both these are soft 'white woods,' pale 



yellowish or reddish-white in colour. The 

 spruce possesses a few fine resin ducts in 

 its autumn-wood which may be seen in 

 cross-sections as very small light spots : 

 they are missing from the wood of the 

 Fig. 63. — Transverse sec- ^ cjlvpr fir 



tion through annual rings of Sliver nr. 



larch timber. (Four times 2. Heart- wood in Old dry timber, reddish-ljrown ; 

 natural size.) splint-wood, pale yellow. 



(a) Larch (Larix europaa D. C). Rings of autumn-wood dark red and 

 very distinct. The branches arise irregularly on the stem, so that 

 the knots on larch boards are scattered irregularly. 

 {b) Soots Pine [Pinus sylvesiris L.). Rings of autumn-wood not so' 

 dark as larch, and contains larger, more distinct resin-ducts. The 

 branches arise in whorls at regular intervals, and the knots are 

 similarly distributed on boards cut irom this tree. 



II.— TIMBER OF DICOTYLEDONOUS TREES. 



GROUP A. 



Vessels of the spring- wood of each annual ring visihle to the naked eye 

 as a distinct circle of pores (Fig. 64) ; autumn-wood denser. 



