BLACK POPLAR. 635 



of the twig beneath them. Many of the lateral buds contain flowers 

 only, and this accounts for the paucity of side-branches, and for the 

 long uninterrupted lines which result from the growth being carried 

 on mainly from the apex of the branch. 



The young branch starts from the older bough at an angle that 

 varies from 60 to 90 degrees, and then makes a clear sweep away 

 from it. But since the branch continues to grow from a terminal 

 bud, and the new portion is in a straight line with the old, the 

 leaves might be expected to hang down like a fringe from their 

 horizontal support, and overlap one another. But the twig in its 

 first stage assumes a position just so much tilted as to obviate this, 

 and, as a further result, a curve is gradually produced in the branches. 

 These long sweeping lines, clearly seen from end to end, make the 

 tree easy to recognise among the many other varieties, which throw 

 out shoots in every direction, and show no continuity of line. 



The lower branchlets are often inclined downwards, and here and 

 there a horizontal one will be found. An unusual feature of rami- 

 fication is the habit which the Black Poplar has of producing wispy 

 twigs from the underside of its branches. These grow straight 

 down, instead of curving upwards round the branches or lying 

 horizontally, as is the case with the Sycamore and many other trees. 



THE CATKIN. 



Among the Poplars some individual trees produce male flowers 

 only, others only female flowers. The flower-arrangement of the 

 Alder, the Hazel, and the Holly should be compared with this. 



The Male Catkins at the end of March, before the leaves 

 appear, burst horn the sticky brown scales that protected the bud 

 during the winter. Inside these scales are longer ones, which are 



