18;") 



Applunl to the bacteriological process in the 

 by which various organic substances containing 

 nitrogen arc changed into nitmtes. The bacteria 

 bringing about the change are called nitrifying 

 bacteria. 



Node. (Latin, nodiw, a knot or joint.) The joints 

 on a stem, at .which the leaves are generally 

 attached. 



Nodules. (Latin, HOtlul-ua, a little knot.) Small 

 rounded swellings, for instance those on the 

 roots of leguminous plants which contain bacte- 

 ria. 



Nut. (Latin, n.r, a nut, a fruit with a hard shell.) 

 Usually applied to hard fruits, which do not 

 split open, and which contain only one seed. 



Organic. (Greek, organon, an instrument or imple- 

 ment.) Belonging to life. The name given to 

 all substances which, although not alive them- 

 selves, are the results of living processes. For 

 instance, wood, starch, hair, bones etc. 



Organism. Any living thing, whether animal or 

 plant. 



Ovary. (Latin, ovum, an egg.) That portion of the 

 pistil of a plant which contains the ovules. 



Ovule. (Latin, owdum, a little egg). The young 

 seeds. 



Parasite. (Latin, pnittttitu*, a fellow boarder, a 

 guest.) An organism, which lives on and obtains 

 its nourishment from another the host. Dis- 

 tinguished from epiphytes which live on but do 

 not obtain nourishment from another organism. 



Petal. (Greek, pehilon, a flower leaf.) One of the 

 leafy bodies, commonly brightly coloured, which 

 usually form the showy portion of a flower. 



Pistil. (Latin, pitttiM-nm, a pestle.) The ovary and 

 stigma (which may or may not be stalked) of a 

 flower. In some plants the pistil is pestle-shaped, 

 hence the term pistil. 



