140 Bulletin Jard. Bot. Buitenzorg, Série III, Vol. V. Livr. 2. 



coco-nut fruit. The haustorium of the embryo is in direct communication with it. 

 From the base of the fruit a number of fibres appear to end abruptly when 

 they reach the sheh. In reahty they pass through into the shell and some 

 of those pass out of the sheU into the tip of the fruit. Other fibres running 

 tangentially to the shell are bent so that they conform to the outline of the 

 shell. This can readily be seen when the pulp of the fruit is removed and 

 the fibres are seen surrounding the stone. In a cross section of a fruit one can 

 readily recognize two kinds of fibres, the brown or black ones immediately 

 surrounding the shell, and the light colored ones scattered throughout the pulp. 



In Figures 60 and 61 Plate Vlll, the cross and longitudinal sections of 

 the fruit with the médium thick shell are seen. The réduction in the thick- 

 ness of the shell and the increase in the size of the pericarp make this form 

 a more désirable type from the point of view of oil production. That is 

 readily seen in contrasting this form with the one previously described. 

 In Figure 60 a ring of isolated fibres of the same color as the shell indicate 

 the fibres which were tangential to the shell and during the growth of the 

 shell were bent conforming to the curvature of the shell. 



The form with the thin shell (Figures 62 and 63) shows a striking 

 différence in the thickness of shell when contrasted with the other two. This 

 comparatively thin shell offers very little résistance to cracking and is esteemed 

 highly by the natives of Africa for that property since the kernel can be 

 secured with so little effort. Except for the thin shell the structure of this 

 form is like that of the other two. 



Variations within a form, 



The variations that exist within a given form can in a measure be seen 

 from the cross sections of several fruits from the thin shelled form taken 

 from différent trees. Thèse form a very interesting séries. For the présent 

 we may assume that the shell represents a definite volume composed of bast 

 fibres set in a matrix of stone cells, like so many straws in a brick. Thèse 

 brown or black fibres can be seen in varying proportions in the cross 

 sections In the médium thick shell Figure 60 we hâve seen them as ring 

 of isolated fibres close to the shell. In Figure 64, in the thin shelled form, 

 they also form a single ring around the shell. In Figure 65 thèse fibres are 

 also in a ring but the individual fibres are coarser. In Figure 62 the fibres 

 form a wider zone around the shell — they show varying cross-sectional 

 areas. The fruit in Figure 67 shows a wider distribution of the fibres; 

 they occupy a comparatively thick zone around the shell. In Figure 66 thèse 

 fibres are scattered throughout the pulp almost to the outermost periphery. 



If we now draw an imaginary circle around each zone of brown to 

 black fibres we find naturaliy, if we include the dark fibres in the éléments 

 of the shell, that the cross sectional area of the shell éléments has been 

 widened so that a form shown in Figure 67 approaches very closely 

 a médium thick shell and a form like the one shown in Figure 66 



