xxx] 



TRIGONOCARPTJS 



121 



more lacunar tissue with a palisade-like hypoder-m : the sclerotesta 

 consists of thick cells which interlace and form an efficient pro- 

 tective shell. Both the sarcotesta and sclerotesta are continued 

 into the apical region as the wall of the long micropyle, the 

 sarcotesta being prolonged beyond the sclerotesta at the apex of 



FIG. 426. Trigonocarpus Parkinsoni. A, longitudinal section; Sa, Sc, if, sarco- 

 testa, sclerotesta, inner flesh; mi, micropyle; PC, pollen-chamber; v, vascular 

 bundles ; m, megaspore and prothallus ; t, tracheal disc ; nt , tracheids in the 

 nucellus. B, transverse section of the upper region showing the sarcotesta, 

 sclerotesta (black) and the micropyle. C, transverse section of T. Parkinsoni. 

 D, transverse section of Trigonocarpus shorensis. (A, C, after Scott; B, after 

 Wild; D, after Salisbury.) 



