200 A TEXT-BOOK OF BOTANY. 



0.56; plums, 0.27 to 0.99; prunes, 0.59 to 0.69; pumpkin, 30.31 to 

 36.25; raspberries, 0.18 to 1.47; strawberries, 0.35 to 1.05. 



Spices. Anise, 16.31 to 18.15; capsicum, 11.20 to 16.81 ; 

 cardamom, 5.50 to 14.77; caraway, 19.43 to 20.25; cloves, 4.73 to 

 7.06; cinnamon, i.oi to 8.00; coriander, 10.94 to 12.03; curcuma, 

 9.18 to 12.56; dill, 6.75 to 21.56; fennel, 16.28 to 17.19; ginger, 

 3.27 to 10.83 ; mace, 4.55 to 7.80; mustard, 15.50 to 39.66; nutmeg, 

 5.16 to 7.12; pepper, 15.18; paprika, 10.9 to 27.16. 



Miscellaneous. Agaricus campestris, 20.63 to 62.94; sea- 

 weeds, 5.56 to 39.25. 



CALCIUM CARBONATE occurs occasionally in the form of a cell- 

 content, being present in tracheae or vessels and tracheids of the 

 heart wood, as well as in the medullary rays and pith cells of 

 certain plants. In this form it is rather characteristic of one or 

 more genera in the following families : Aceraceae, Anonaceae, 

 Cornaceae, Cupuliferae, Rosaceae, Salicaceae, Sapotaceae, Urti- 

 caceae, and Zygophyllaceae. When present it almost completely 

 fills the cells, and may be overlooked or referred to as resin unless 

 its identity is proved by the use of certain reagents. Like the 

 other carbonates, it dissolves with effervescence on the addition 

 of hydrochloric acid, nitric acid, acetic acid, etc., and in this way 

 may be detected. 



Calcium carbonate is present in special structures known as 

 Cystoliths. The latter are protuberances of the cell wall into the 

 cell, and consist of a stalk and a body (Fig. 113). The stalk 

 consists of a simple core of cellulose on which more or less silica 

 is deposited. The upper or body portion consists of a more or 

 less irregular spherical or ellipsoidal deposit of calcium carbonate. 

 These are found in the parenchyma cells in roots and barks and the 

 subepidermal cells of leaves. They are also found in epidermal 

 cells, as in the short hairs of Cannabis sativa. Cystoliths occur 

 in certain genera of the Acanthaceae, Borraginaceae, Cucurbi- 

 taceae, Gesneraceae, Oleaceae, Ulmaceae, Moraceae, and Urticaceae. 



Cystoliths occur in a number of modifications, and, while they 

 are usually simple, yet in some of the Acanthaceae and Urticaceae 

 branched cystoliths occur. In some of the genera of the Cucur- 

 bitaceae 2- to 4-adjoning cells may have cystoliths, and hence are 

 known as " double cystoliths." The cystoliths found in hairs, as 



