YAMPOLSKY: Stndy of OU palni. 163 



wliich contaiii tlie so-called reserve cellulose are évident. Fij^iire 145, Plate 

 XVII shows several of thèse cells in lonf^itudinal section. The intercommuni- 

 cating- pits are aiso shown. In cross section thèse cells show 'a polygonal 

 outline with strongly thickened walls and pits. Thèse cells are filled with 

 fats, oils, aleuron grains and the proteins from the cytoplasm and nucleus. 

 The endosperm cells to-gether with their contents snpply the embryo with 

 hydrocarbons, carbohydrates and proteins. 



In the process of germination we hâve two contrasting phenomena — 

 an endosperm which is gradually diminishing and an haustorium that is 

 increasing in size. Thèse, as we know, are correlated phenomena. 



The endosperm throiigh its zones, throiigh the state of the cell walls 

 and through its oil or fat drops and aleuron grains registers the processes 

 of dissolution of the tissue. 



If a seed is eut through in a stage of germination two distinct zones 

 can be made out with the naked eye. Such zones can be seen in Figures 

 102 to 105 Plate XI and Figures 127 and 130, Plate XVI. The sharp line 

 of démarcation between the two is striking. The inner zone — the one near 

 the haustorium, is of a soft cheesey consistency, the outer zone is quite 

 solid and résistant. 



If we now examine the cells of the endosperm in such a condition 

 we find a corresponding différence in the cells too. Figure 144, Plate XVII 

 is a section of the endosperm in a stage shown in Figure 130, Plate XVI. 

 The lower dotted zone is the cork layer, the next zone is that of the 

 intact cells, the third zone with the large fat or oil globules and the 

 empty cells is the soft zone that we hâve mentioned above. The différence 

 in the two zones lies primarily in a différence in the amount of cellulose. 

 In the soft zone much of the so-called reserve cellulose has been removed 

 from the walls, the middle lamellae too hâve disappeared so that the cells 

 are no longer rigid and thus they form a soft tissue. 



There can be no doubt that the protoplasmic communication between 

 the cells which KOHL ('^) has described iii the endosperm cells of 

 Phyteleyhas macrocarpa and Coleococcas carolincnsis are also to be 

 found in the cells of Elaeis. Thèse protoplasmic bridges are digested 

 so that passage of drops of oil or fat is facilitated through the pits, 

 accounting for so large an accumulatioii of drops in that région. A free 

 hand section of the endosperm stained with Sudan III, brings out in 

 a most striking fashion thèse zones. This can be made out with the 

 naked eye. 



If we examine the cells more critically we find that the aleuron grains 

 also act as indicators. In the zone where active digestion is going on 

 there are fevver grains. In sections from material which has been imbedded 

 in paraffin and has been run up through the varions percents of alcohol 

 and then into xylol, tiie fats and oils are naturally absent. The aleuron 

 grains apparently remain unaltered, at least their distribution corresponds 



