246 PLANT ORGANS OR PARTS OF PLANTS. 



whether to be found in the cell wall or in the proto- 

 plasm of endoderm cells. Probably in protoplasm 

 (Mayer). Igasurine probably does not exist. 



IGNATIA. 



The seeds of Strychnos Ignatia, Bergius, a stout climb- 

 ing plant indigenous to the southern Philippine Islands. 



Description. — Dried ignatia beans vary considerably 

 in size, and are of dull grayish color and. irregular 

 ovoid outline. In general they are 2.5 cm. long and 

 somewhat less broad and thick. Frequently there is one 

 large, curved side seed and three or four smaller, flatter 

 surfaces, but some seeds are altogether irregular. The 

 hilum is generally readily seen and sometimes there are 

 remnants of the seed-coat covering the homy surface. 



Histology. — When soaked in warm water, the large 

 endosperm can be divided into two portions, enclosing 

 between them a cavity in which lies the embryo, with its 

 small radicle and leafy cotyledons. The cells resemble 

 those of nux vomica, but hairs are absent. 



Chemistry. — The constituents are those of nux vomica. 



SINAPIS. MUSTARD. 



Sinapis is the seed of Sinapis nigra, L., a member of the 

 nat. ord. Cruciferce, now cosmopolitan. 



Description. — The seeds are small, about 1.5 mm. 

 in diameter, spherical, slightly umbilicated, and of a 

 dark-brown color. Under the magnifying glass the sur- 

 face is finely reticular. 



The powder is green. 



Histology. — The epidermis consists of colorless, hex- 

 agonal, tubular cells, whose inner walls undergo the 

 mucilaginous modification upon the addition of water. 

 Just beneath this row of cells th^re is a layer of palisade- 

 like cells whose inner walls are thickened and deeply 



