Tkiselton-Dyer. — Morphological Notes . 425 
In Pinus a structure may be found which at first sight is 
similar. Fig. 1 is from a life-size photograph of a piece of 
‘ yellow deal 1 ( Pinus sylvestris ) taken from an old building 
at Kew, and without further history. In this case the 4 traces ’ 
penetrating the annual rings are not mere c leaf-traces } but 
are the fibro-vascular cylinders of limited branches. 
Fig. 2 shows a transverse section of the same specimen. 
This has passed through a 4 branch-trace , 5 and shows its 
termination at the fourth annual ring. 
In a specimen of the wood of Pinus glabra from N. America, 
presented to the Kew Museum by Prof. Sargent, the 
appearance presented in a tangential section near the centre of 
the trunk closely resembles those that occur in Araucaria. 
The persistence of leaf-traces affords apparently a decisive 
character for assigning fossil Coniferous woods in which they 
occur, at any rate to the Araucarineae . Their absence is not 
however equally conclusive, as I am at present in possession 
of no evidence that they are continued after the leaves 
are finally thrown off in very old stems by the disruptive 
action of circumferential growth. They have, however, been 
traced to the exterior of the wood in an old stem grown at 
Kew which shows at least sixty annual rings, and in which 
all remains of the leaves have entirely disappeared. It is 
possible therefore that the leaf-traces may continue to extend 
indefinitely although any foliar function which may belong to 
them has ceased. 
I must express my obligations to Mr. L. A, Boodle, F.L.S., 
who has taken much kind trouble for me in making the 
photographs. 
