152 TUANSACTIONS AND rROCEEDIXGS OF THE [Sess. LXiii. 



The upper part of the tree, which I may call the 

 virgata or serpent part, was densely covered with long 

 thick needles, occurring in bi-, tri-, and quadrifoliar spurs. 

 The bifoliar spurs of the upper part were much longer 

 than those of the lower or normal part, the average 

 difference being 2 '2 inches. Bifoliar and trifoliar spurs 

 occurred all over the tree, but the quadrifoliar spurs 

 were entirely confined to the upper part. The quadrifoliar 

 spurs were heterophyllous, the fourth needle being shorter 

 and thinner than the other three, which averaged 6 "7 8 

 inches in length, while the fourth needle averaged 4 '08 

 inches, it is therefore 2-V inches shorter than the other 

 three. In addition to being the smallest, it is the highest 

 inserted needle of the sheath. A longitudinal section 

 shows that it belongs to the interfoliar bud, being, in 

 fact, a metamorphosed bud scale. The other three 

 needles were produced by the last three leaves of the 

 branch of limited growth in the normal manner, and 

 tliey are therefore arranged round the apex of the 

 branch, with their bases nearly in the same plane ; but 

 the base of the fourth needle is much higher, its point 

 of insertion being opposite that of the first scale leaf 

 of the interfoliar bud, as may be seen from the photo- 

 micrograph. Tliat the fourth leaf is a subsequent 

 formation may be seen by a transverse section just 

 above the leaf sheath. The three larger and first formed 

 leaves together form a circle, tlieir inner sides converging 

 at angles of 60°. The regularity of this arrangement, 

 however, is broken by the fourth leaf, which has grown 

 up between the others, flattening their inner angles, and 

 giving them a more or less polygonal outline. The 

 fourth needle itself is plano-convex, but at one of its 

 angles there is a peculiar outgrowth which has been 

 caused by the crushing of the other leaves. 



A transverse section of the three larger needles showed 

 them to have the typical structure. The resin canals were 

 not in contact with the hypoderm, as in the the Scots pine, 

 but were embedded in tlie mesophyll, and though varying 

 in ninnber in different leaves, still they all showed the 

 median upper resin canal so typical of a certain number of 

 pines, including Finns Laricio. Tlie vascular bundle was 



