GLOSSARY 



Some of the more technical terms about which there might 

 be some doubt, as they are not always accompanied by explana- 

 tions in the text, are here briefly defined. 



Anatomy The study of the details and relative arrangements of 



the internal features of plants; in particular, the relations of the 

 different tissue systems. 



Bracts. — Organs of the nature of leaves, though not usual foliage 

 leaves. They often surround fructifications, and are generally 

 brown and scaly, though they may be brightly coloured or merely, 

 green. 



Calcareous. — Containing earthy carbonates, particularly calcium car- 

 bonate (chalk). 



'Cambium. — Narrow living cells, which are constantly dividing and 

 giving rise to new tissues (see fig. 33; p. 57). 



Carbonates, as used in this book, refer to the combinations of 

 some earthy mineral, such as calcium or magnesium, combined 

 with carbonic acid gas and oxygen, formula CaCOs, MgCOg, &c. 



Carpel. — The closed structure covering the seeds which grow attached 

 to it. The " husk " of a peapod is a carpel. 



Cell. — The unit of a plant body. Fundamentally a mass of living 

 protoplasm with its nucleus, surrounded in most cases by a wall. 

 Mature cells show many varieties of shape and organization. See 

 Chapter VI, p. 54. 



Centrifugal. — Wood or other tissues developed away from the centre 

 of the stem. See fig. 65, p. 97. 



Centripetal. — Wood or other tissues developed towards the centre of 

 the stem. See fig. 65, p. 97. 



Chloroplast. — The microscopic coloured masses, usually round, green 

 bodies, in the cells of plants which are actively assimilating. 



Coal Balls. — Masses of carbonate of calcium, magnesium, &c., gener- 

 ally of roundish form, which are found embedded in the coal, and 

 contain petrified plant tissues. See p. 28. 



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