BENNETTITEAE 573 



in a small disc, while the adjacent tissues of the pedicel 

 pass over into the testa. The seeds have a length 

 of over 3 mm., not counting the micropylar tube, and 

 a diameter of nearly 2 mm. The seeds which have 

 been investigated were fully ripe, for each, when well 

 preserved, contains a large embryo, nearly filling the 

 cavity (see Figs. 204, s, 203, C, and 205). The testa 

 is made up of three layers, an inner and outer layer 

 of small comparatively thin-walled cells, and a middle 

 layer of large square or palisade-like cells, which 

 appear almost solid, an appearance which may be due 

 to extreme thickening of their cell-walls (Fig. 203, C 

 and D). 



Towards the micropyle, the middle layer of the 

 testa is greatly dilated, and is here several cells in 

 thickness ; it is surrounded by the external zone, which 

 in this part is very distinct (Fig. 203, D). The inner 

 layer of the testa forms the internal tube of the actual 

 micropyle, which, however, in these ripe seeds is closed, 

 as is usually the case (see Fig. 203, D, which represents 

 a somewhat oblique longitudinal section through the 

 micropylar end of a seed). The distal end of the 

 micropyle (not shown in our figure) narrows out con- 

 siderably, owing to reduction of the middle layer of 

 cells, but appears to be somewhat dilated again at the 

 extremity. The testa is everywhere closely adherent 

 to the surrounding tissue of the pericarp. In the body 

 of the seed, the nucellus is only to be traced as a 

 structureless membrane (see Fig. 203, C, n), but it is 

 better preserved at the apex (Fig. 203, D, m). 



The embryo so nearly fills the cavity of the seed 

 that the latter may be spoken of as exalbuminous, 



