150 FRUITS. 



(76) Coriander Fruit. 



The fruit of Coriandrum sativum, Linn. (N.O. Umbellif eras) . 



The dorsal portion exhibits in transverse section : 



(1) An outer epidermis composed of tabular cells which in 

 surface view are seen to be polygonal, and have slightly 

 thickened, pitted walls. It is often partially thrown off, espe- 

 cially from the intercostal regions ; it is provided with stomata, 

 and in some of the cells a prismatic crystal of calcium oxalate 

 may be observed. 



2) A tissue, corresponding to the mesocarp, which has under- 

 gone considerable differentiation, and in which the following 

 layers can be distinguished : (a) an outer layer of tangentially 

 elongated parenchymatous cells ; (b) a well- developed layer of 

 sclerenchyma, traversed by fibre-vascular bundles, and forming 

 a continuous and very thick protective tissue throughout the 

 entire dorsal portion of the mericarp ; the cells of which this 

 layer is composed are elongated, have thick, pitted walls and 

 cross in different directions ; (c) one or two rows of flattened 

 thin- walled cells ; (d) two or three rows of large, irregular 

 polygonal cells with very thick, pitted walls. 



(3) An inner epidermis of flattened, tangentially elongated 

 cells which in surface view are seen to be rectangular, four or 

 five times as long as they are broad, and all elongated in the 

 same direction. 



(4) A seed-coat consisting of a' single layer of pale yellow 

 polygonal cells with slightly wavy walls. 



(5) An endosperm made up of thick walled polygonal cells 

 containing aleurone grains, fixed oil, and small rosette- crystals 

 of calcium oxalate. 



The structure of the commissural portion of the fruit is 

 slightly different from that of the dorsal portion ; the scleren- 

 chymatous layer is absent, and the mesocarp is traversed by two 

 large secretory ducts (vittse). 



The diagnostic characters of powdered coriander fruit are : 



(a) The epidermal cells with prismatic crystals. 



(b) The fibrous sclerenchymatous layer of the pericarp. 



(c) The large sclerenchymatous cells in the inner part of 

 the pericarp, to which 



(d) The inner epidermis is often attached. 



(e) The large secretory ducts. 



(/) The minute rosettes of calcium oxalate in the 



The last two characters are found in other umbelliferous 

 fruits. 



