YAMPoLSKY: Study of OU indm. 145 



The cells pass over gradiially iiito the dark browii cork cells wiili iio 

 cell centeiits wliicli are directiy in contact with the eiidosperm. The thiii 

 layer betweeii the concave surface of the operculiim aiid the- endosperm 

 iii the viciiiity of the embryo is coniposed of the same kind of cells. A 

 very thiii zone of spiiidie cells surrouiids the aborted opercula. 



The endosperm tissue does not differ from the endosperm tissue in 

 the shelled forms which we shall discuss later. 



The pericarp tissue in a sîate prior to ripening of the fruit is made 

 up of polygonal cells. When the process of ripening is complète thèse 

 cells become rounded. At low magnifications the orange colored fat glo- 

 bules indicate the distribution of the cells of the pericarp (Figure 80). The 

 process of ripening has been recently described by TOBLEE< (^^) although 

 no figures are given to show the condition of the cells prior to and during 

 the process of ripening. 



It is not unusual to find two and three embryos in a seed and in 

 rare cases also four (Figures Q9— 104 Plate XI). in each case there is no 

 communication between the embryos, they are separated from each other 

 by stone partitions, in the pisifera form two embryos are common and 

 several with three hâve been seen. 



The varions steps in the development of the oil palm fruit prior to and 

 after fertilization are being investigated by my former colleague Dr. CaRL 

 Heusser of the Algemeene Proefstation der A.V. R.O.S. Medan Sumatra. 



For a discussion of the literature on the anatomy of the palm fruit 

 WlESNER's (•*") "Die Rohstoffe des Pflanzenreiches" is invaluable. Attention 

 must be called to the similarity of the structure of the bundles (fibres) in 

 the shell of Elaeis and Attalea (WlESNER I. c. Bd. 111 p. 810 Figure 285. 



Summary, 



1). Varietal distinctions are based on fruit characters. 



2). Our fragmentary genetic évidence points to three types of fruit 



which may be constant — thick, médium, and thin-shelled. 

 3). Différences in fruits are différences in the proportions of pericarp, 



shell and kernel. 

 4). Within a given form great variation exists. 

 5). In the shell-less form, a shell is entirely lacking although the région 



of the shell is présent hi a modified state. It may very well be a 



pathological form. 

 6). Form with accessory floral parts may merely be a teratological form 



and cannot be considered of spécifie rank, 

 7). Fibres can readily be traced in the pisifera form. 

 8). The so-called parthenocarpic fruits contain ôil in the pericarp like 



the normal fruit-pit is solid throughout. 

 Q). Différences in shell thickness are différences in the proportions of 



bast and stone cell éléments. 



