INFLORESCENCE AND FLOWERS FRUIT AND SEED. 135 



scribed above are removed from the embryo, it is then 

 possible to gently separate the cotyledons and see the 

 minute plumule and radicle to which they are joined 

 (Fig. 36) ; on removing one cotyledon the plumule will 

 be seen imbedded in a slight depression at the base. At 

 this point there is a little room to spare, not quite filled 

 up by the radicle and plumule ; a minute remnant of 

 endosperm may occasionally be found here, not having 

 been entirely absorbed by the developing embryo. 



The cotyledons and embryo are composed of a deli- 

 cate epidermis inclosing the whole (Fig. 37, e), and very 

 thin-walled cells forming the main mass of tissue in 

 which the vascular bundles run. These bundles are 

 scattered in the thickness of the cotyledons, ready to 

 convey fluids to and fro on germination, and already 

 contain lignified vessels in the xylem and sieve-tubes in 

 the phloem. 



The iso-diametric, closely-packed cells of the cotyle- 

 dons are filled with reserve materials, consisting of large 

 quantities of starch grains imbedded in proteids and 

 tannin. Here and there are scattered cells filled with 

 brown pigments and containing tannin ; some cells also 

 contain oil-drops. Traces of sugar (quercite), certain 

 bitter principles, acids, and mineral substances also occur 

 in the tissues. 



