164 BULLETIN jARD. BOT. BUITENZORG, SÉRIE III, VOL. V. LiVR. 2. 



to the zones, in the emptied aiid crushed cells isolated grains may 

 occasionally be found. 



The cell walls show characteristic chancres, hi direct contact with 

 the haustorinm is a mantle or zone of crushed cells which can hardly be 

 recognized as cells. Thèse cells hâve ail lost their wall thickenings and 

 what remains are the shrunken primary walls. 



The cells pass gradually into cells that show varions stages of cell 

 wall dissolution. The cells are just beginning to be crushed due to the 

 pressure exerted by the expanding haustorium and because of their loss 

 of wall reinforcement. In cross section in this stage, thèse cells form a 

 net like structure — the cells are diamond shaped. 



The cell walls of the unsoftened tissue show no changes but with 

 the graduai encroachment of the haustorium they will pass through the 

 same changes described above. 



From an examination of the zones of the endosperm one can readily 

 visualize the process of dissolution. It is decidedly obvions that the 

 enzymes secreted by the haustorium act opun a zone for some distance 

 beyond the région of their origin as we can seen from the zones. The 

 pectinase and cytase, if thèse be the enzymes that are responsible for the 

 dissolution of the middle lamellae and reserve cellulose respectively, hâve 

 begun to act before the cell contents hâve been absorbed by the haustorium. 

 Proteolytic and lipalytic enzymes pass beyond the active zone of absorption, 

 preparing in advance the food for the haustorium. 



The endosperm through its cell walls, through its aleuron grains and 

 oil drops indicates the processes of digestion going on. 



The crushed primary cell walls arc absorbed and they are not piished 

 ahead of the haustorium to remain undigested as described for grasses 

 and Phoenix. This agrées with Green's ('") observations in Livistonia. 

 Moreover the région of cell walls directly in contact with the haustorium 

 gives distinctly the sugar reaction with Fehlings solution. 



The crushed cells are in direct contact with the haustorium and they 

 are found closely pressed against the lobes and in the spaces between 

 the lobes (Figures 130 and 131, Plate XVI). In Figure 142 intimate relation- 

 ship is shown between thèse crushed cells and the haustorium. The 

 cells of the outer layer can be seen in the rôle of digesting the cell walls 

 and storing up starch grains. 



After the endosperm is absorbed the space is occupied by the haustorium. 

 Nothing remains but the cork zone with the irregular ends of a few cells. 



The starch grain serves as an indicator of the processes going on 

 within the haustorium and the embrj'O proper. The size, the form and 

 the condiHon of the starch grains is em|:»loyed for that purpose. Attention 

 must be called hère to the starch grains that are being inverted into sugar. 

 The action apparently begiiis from the hilum and radiâtes outward (Figures 

 137 and 138, Plate XVII). 



