308 SCIENTIFIC AND APPLIED PHARMACOGNOSY 



Constituents. Citric acid, 3 per cent; malic acid, 8 per cent; 

 mucilage, 25 per cent; an uncrystallizable sugar, 30 per cent; also 

 citrates, malates and mineral salts. 



CYDONIUM. Semen Cydoniae, Quince Seed. The ripe seeds 

 of Cydonia vulgaris (Fam. Rosacese), a shrub indigenous to south- 

 western Asia and extensively cultivated. The fruits are gathered 

 in the fall when they are ripe, the seeds removed and dried. The 

 commercial supplies come chiefly from southern Russia and Portugal. 



Description. Single or in agglutinated masses; the individual 

 seeds being somewhat ovoid and compressed, with 2 or more sharp 

 ridges, convex on one side and flattened or somewhat shallow 

 on the other, from 5 to 10 mm. in length and from 2 to 6 mm. in 

 breadth; outer surface reddish-brown or brownish-violet, more or 

 less covered with adhering grayish gum; fracture short; inner sur- 

 face showing a large yellowish-white embryo and a thin, reddish- 

 brown seed-coat, which is easily separated by placing the seeds in 

 water; inodorous; taste mucilaginous, slightly aromatic, similar 

 to that of benzaldehyde. 



Inner Structure. A mucilaginous epidermal layer, the cells being 

 tangentially elongated and upon the addition of water swelling to 

 such an extent as to separate the thin cuticle from the rest of the wall; 

 several rows of thick-walled sclerenchymatous fibers, having a brown- 

 ish-red, amorphous content; a layer of colorless, thin-walled cells; 

 inner epidermis of somewhat tubular cells having a brown amorphous 

 content; an endosperm composed of 5 to 7 layers of polyhedral cells; 

 cotyledons of thin-walled cells, containing an oily cytoplasm and 

 numerous aleurone grains, the latter from 0.006 to 0.028 mm. in 

 diameter. Starch occurs only in the unripe seeds. 



Powder. Yellowish-red or reddish-brown; fragments of seed- 

 coat with polygonal, mucilaginous epidermal cells, the walls of which 

 are readily stained with methylene blue; a number of rows of scleren- 

 chymatous fibers with strongly thickened walls and brown contents; 

 several layers of elongated, thin-walled cells resembling the "tube 

 cells " in cereals; a colorless layer with minute starch grains; and an 

 inner epidermis, the cells of which contain a brown pigment. The 

 perisperm consists of several layers of more or less obliterated cells. 

 The outer layers of the endosperm, as well as the cells of the embryo, 

 contain aleurone grains and a fixed oil. 



Constituents. Mucilage, 22 per cent, yielding on hydrolysis 

 oxalic acid, and forming arabinose, on treatment with dilute sul- 

 phuric acid. It is distinguished from cherry gum and the mucilages 

 of other Mimosese in being precipitated upon the addition of creosote 



