Flowers. 165 



humming-birds, etc., which, as we shall see, may be of 

 service in the production of seeds. The petals are not 

 absolutely necessary to reproduction, and are often wanting. 

 At d, e is a stamen, made up of d, the filament, and e, 

 the antJier. The anthers contain small grains, known as 

 pollen grains, which produce the sperm, and are therefore 

 absolutely necessary to the production of seeds. 



FIG. 87. 



Longitudinal diagram of a Flower, a, the receptacle; b, sepal; c, petal; d, fila- 

 ment ; e, anther (filament and anther constitute the stamen) ; f, ovary ; g , style ; 

 h, stigma (ovary, style, and stigma constitute the pistil) ; /, pollen tube descend- 

 ing through the style to the ovule ; n, cavity of the ovary ; /, the ovule consisting 

 of the stem or funiculus, m ; two coats with an opening, /, through them (micro- 

 pyle) at the lower end; the nucellus, o, and the embryo sac, i. 



At/, g, h is \htpistil, which is composed of the enlarged 

 basal portion (/), known as the ovary, the more or less 

 slender prolongation of this (g), called the style, and a por- 

 tion of the style (//) near the apex, termed the stigma, 

 which is usually somewhat rough and sticky so as to catch 

 and hold the pollen. Sometimes the style is very short, 

 and the stigma appears to rest on the top of the ovary. 



Within the ovary and growing to it are the ovules (one 

 shown aty ), which are destined to become the seed. The 



