OX THE FERTILIZATION 



., „. iacont mm ta the form of a delicate membranous sac containing a stratum of 



,"» • . 2 orial Tae cells of the external epidermis beneath it are now no longer 



Si' r" Tbir Shaped, and open externally by wide circular orifices (Plate V, 



r<AumoMT f W» onm j -i tnceable on the inner surface of the 



fk. 19), markings corresponding to which are traceame o 



detached cut 



The crib still adhere laterally to one another with considerable tenacity, and large sheets 

 „f them an therefore be readily detached. This is not so with the cells of the hypodermis, 

 v, Lb are degenerate, softened, and so much loosened from one another as to form an 



„coher,nt gelatinous stratum (Plate V, fig. 20), save where the under portions of the deepest 



ae. adhere to the outer surface of the achene to form a pseudo-cuticular coating to it (Plate V 

 18^ The achones measure about 102 x 0-7 mm., and are of a bright yellow colour 

 if walls have a total thickness of 0-089 mm. Beneath the pseudo-cuticular coat is a 



y 



, „_.. ft .d 



triune 



uni built up of masses of what appear to be very small, completely sclerosed cells 

 >lunmar groups, an<l which represent the ultimate product of the stratum of small cell 



external to the internal epidermis of the immature ovary (Plate V, fig. 18) 



! 4 layer is about 0-0:3 mm. in thickness. Internal to it is one about 0*056 mm. in thickness 

 and oontist.i - of the modified internal epidermis. The cell cavities are greatly reduced ii 



in 1 are represented by a mere system of curiously ramified, slender channels (Plate V 



j 



fig. !8). So complete and uniform has the sclerosis around these been, that the sites 



< responding with the original cell-walls are only indicated here and there by the apposition 



4 the somewhat dilated extremities of the fine lateral twigs of the large oblique or vertical 



channels. 



The stigma and the distal portion of the style remain persistent and unaltered, but the 

 has il portion of the latter ultimately undergoes changes parallel to those taking place in the 

 superficial strata of the ovary. As a result of these, the cuticle becomes detached as a sort 

 »f tubular diverticulum of the ovarian cuticular sac, and the deeper tissues gelatinise, so that 

 it lieconiM difficult without special care to procure specimens of the flowers with the styles 

 still i ihcrent. 



The maturo seeds are somewhat difficult to remove intact from the interior of the 

 achenes, due to the small size and resistent coats of the latter. Soaking in sulphuric acid, 

 ho we jr, facilitates tha process, as, under the influence of this, the achenes tend to separate 

 more or less completely into two lateral halves and allow the seeds to escape. They are 

 provided with a thin outer coat, consisting of empty flattened cells in several strata, corre- 

 sponding to those of the secundine and nucellar epidermis of an earlier period of development. 

 Within this are two strata of large cells crowded with oil globules and representing the 

 mature stage of the nucellar parenchyma. The embryo is of relatively large size, and is 

 I miewhat curved upon itself, so as to leave a small space on the funicular aspect of the seed- 

 cavity unoccupit I, in which apparently a little true endosperm is present. The short radicle 

 is directed to the apex, and the large cotyledons to the base of the seed. 



I)— Characters of female flowers in mature receptacles which have not been 



entered by insects. 



n the majority of cases the flowers retain the characters of those in receptacles 

 at the stage for the access of insects, or at all events merely show modifications dependent 













