Yampolsky : Study of OU palni. 



113 



which encloses tlie next succeeding leaves, tlie first leaves hâve tlie tendency 

 to be tubular. As growth iiicreases, the outermost leaves are reflexed 

 and tliey become concavo-convex due in a great measure, as we sliall 

 see later, to tlie fact that the segments which go to make up thèse leaves 

 are held together in a defiiiite fashion. As the young plant continues to 

 o-rov/ the succeeding leaves increase in size and the first indica'tion of the 

 splitting of the leaf occurs, usually at the tip which becomes two-parted. 

 With each succeeding leaf the progressive division of the leaf continues 

 so that at the base of the formerly undivided blade a pair of leaflets appear. 

 in the next succeeding leaves the number of pairs of leaflets increases. 

 The end of the leaf except for its divided tip retains its more or less undivided 

 character. In plants as old as two years this juvénile character of the leaf 

 is still retained although the number of pairs of leaflets has increased. 

 The foUowing observations taken on plants in the „Cultuurtuin" (Experiment 

 Garden) at Buitenzorg give the distribution of the leaflets according to the 

 âges of the plants. 



It is interesting to note that in many of the juvénile leaves séparation 

 of the leaflets is incomplète. The séparation begins at the midrib and 

 progresses part way towards the periphery. It is not uncommon when 

 going through a pianting of seedlings to see leaves perforated in a manner 

 characteristic of some Aroids. 



The maximum development of the leaf occurs in the fifth year in 

 Sumatra and the pairs of leaflets vary in number from 130 to 160 judged 

 from the several countings that hâve been taken. In other countries, notably 

 in the African districts where the oil palm naturally grows, the full matu- 

 rity of the leaf is reported to occur when the plant is seven years old and 

 when there is a marked upward growth of the stem. 



