YaMPOLSKY: Sfitdy of OU palm. . l23 



It will be remembered that in the mature leaf the furrow deliminating tlie leaf 

 blade from the rest of the leaf runs more or less vertically. The initial 

 stages are exactly Hke those described for the fan palms by ElCHLEK {^) 

 such as Prifchardia, Livisfoiia etc, where the furrow is horizontal. 



It is comparatively simple to follow the various stages from the undif- 

 ferentiated to the mature leaf. in the young stages .which show no outward 

 indication of the présence of 'Anlagen' for segments, their présence can he 

 shown either by pressing a cover slip down gently and staining with a 

 suitable dye or by partial macération of the leaf and then observing it. As 

 a rule the number of segments observed on either side of what is to be 

 the mid-rib is five. That number however is not fixed. I hâve found 7 and 

 8 segments in each half. 



The segments arise as individual units from 'Anlagen' and they maintain 

 their individuality throughout. The same process, of splitting as described 

 for the mature leaves results in a folded leaflet. 



In Figure 1, Plate I the leaf represented is already in an advanced stage 

 of development, the segments are definitely deliminated. It is to be iioted that 

 the segments hère arise in a more or less horizontal plane. The leaflets do 

 not reach to the periphery of the leaf blade, there is a comparatively tliick 

 undivided strip, much wider than we hâve noted for an équivalent stage that 

 is to give rise to the fully divided leaf. The tip of the leaf is very strongiy 

 developed and the very apex ends in a number of branched hairs (Figure 2 

 Plate I). The présence of this comparatively thick strip no doubt is associated 

 with the fact that no séparation of segments occurs in the first leaves. 



Further stages of development are seen in Figures 2 and 3. The leaf 

 shown in Figure 2 has eight segments in one half of the blade, the one in 

 Figure 3 has six. Thèse segments, however, never separate but they are held to- 

 gether by the thick strip of tissue at the periphery of the leaf blade. The respec- 

 tive halves of the segments corresponding to the respective leaflets in the 

 divided leaf, pass through the same splitting and they hâve the morphological 

 équivalent of a mid-rib. The halves along the line of cleavage separate 

 from each other. This process of splitting of the segments which is not 

 foUowed by the séparation of the segments from one another results in a 

 lanceolate leaf which shows distinct folding where it is constricted and 

 consequently the fluted appearance at the base of the blade to which we 

 hâve already referred (Figure 7, Plate I). The formation of slits on the outer 

 and inner surfaces occurs after the segments hâve exerted a pressure on 

 the sides of the lamina causing splitting of the enveloping tissue between 

 two segments, precisely in the same way that we hâve noted for the older 

 leaf. At unfolding of the leaf however, the séparation of the segments along 

 adjacent edges does not occuur, as it does in the mature leaf. Following 

 the fifth or seventh leaf splitting one division of the tip of the leaf occurs, 

 a condition so very typical also for the coconut palm. Then follow leaves 

 with a single pair of leaflets at the base of the blade more or less completely 



