Yampolsky : Siiidy of OU puLin. 



149 



our kiiowledge of germination in palms as well as in otiier nionocotyledons. 

 TSCHIRCH P^) and liis school hâve doue mucli to furtlier investigations 

 along tliat line. Still, tlie number of detailed investigations on tlie relation 

 between haustorium and endosperm are few. We hâve yet to await a 

 thorougli investigation of so conspicuoiis an organ as the haustorium of 

 the coco-nut in its relation to the endosperm, ahhôugli the cultural phase 

 of that pahii has been exploited inteiligently for countless centuries. The 

 fruit of tlie oil pahn because of its size and because it offers no serious 

 technical difficuities is a most favorable object for investigation. 



If we turn now to the gross détails of germination we can follow 

 the steps in the process very readily. We hâve seen that the fruit of the 

 oil palm can roughly be divided into pericarp, shell and kernel. When the 

 fleshy, oil containing pericarp is removed the germ pores of the seed 

 become visible. As a rule only one is functional since the rule is that one 

 embryo develops in each seed. Attention has also been called to the 

 prese[ice of two, three and four embryos within a single seed. PFITZEK (2^) makes 

 the foUowing grouping of palm fruits based upon the présence or absence 

 of definite régions for the émergence of the embryo during germination. 



1). No definite locus in the 

 shell — the embryo breaks-through 

 the shell as a resuit of internai 

 pressure exerted by the growing 

 embryo. 



2). Shell provided with de- 

 finite areas less résistant than the 

 rest of the shell — strands of soft 

 tissue pass through those areas 

 enabling the embryo to push its 

 way through with but little ré- 

 sistance. 



3). Présence of definite open- 

 ings in the shell provided with 

 plugs which are pushed out 

 through the openings(germ pores) 

 at germination. 



The variations that exist in 

 the last group hâve been indicated 

 by Pfitzer. 



The fruit of the oil palm 

 belongs to the third category. 

 In the discussion of the fruit we 

 hâve described the operculum. 

 The pores run through the whole 

 thickness of the shell so that the thickness of the shell apparently has no 



Text Figure 57. 

 F — fibres radiating from the operculum, 

 through the germ pore into the pericarp. 

 P — operculum in cross section. E — embryo. 

 E C — cavity in v.'hich embryo lies. 1 C — 

 intercomminicating canal. F — fissure in en- 

 dosperm (homologous with large cavity in 

 coco-nut) S — shell. E — endosperm. C — cork 

 layer surrounding endosperm X 2'/v. 



