THE FLOWER. 43 



larged upper end. That portion of the filament between the 

 anther-lobes is called the connective. The filament is not an 

 essential part, and when wanting the anther is said to be ses- 

 sile. When the filaments are united into a tube surrounding 

 the pistil, as in the Mallow, they are said to be monadelphous. 

 If they are united into two sets, as in Dicentra, they are dia- 

 delphous ; if in three sets, triadelphous, and so on. The an- 

 thers are united into a tube (syngenesious) in the Compositse 

 (Sunflower, Dandelion, etc.). Make a transverse section of the 

 anther ; two or four cavities may be seen with the aid of a 

 lens, and these are filled with a yellow dust, which on ex- 

 amination with the microscope proves to be small, round 

 bodies, called pollen. The opening, dehiscence, of the an- 

 ther at maturity for the discharge of the pollen commonly 

 takes place along a line the whole length of each cell. But 

 in the Sassafras, Barberry, etc. the opening is by a lid or 

 valve. In the Azalea, Pyrola, etc. the pollen escapes by a 

 pore at the top of the anther. 



13. The number of stamens may vary from one to many in 

 the flowers of different species. They are, however, definite 

 and few in number in the majority of cases. Their size, 

 length and place of insertion may also vary. In the Mint 

 family often two of the stamens are long and the other two 

 short ; they are then said to be didsmamous (Gr. di, two ; 

 dynami, power, strength). In the Mustard family four of the 

 stamens are long and two are short (Fig. 64), called tetradyn- 

 amous (Gr. tetra, four). As regards the insertion 



of the stamens, they are hypogynous when attached 

 below the pistils ; perigynous when attached to the 

 calyx tube surrounding the pistil ; and epigynous 

 when situated with the sepals on the ovary. They 

 are epipetalous when attached to the corolla. 



14. The pistil (Fig. 65) consists of three parts — 

 namely, the ovary or lower enlarged part which 

 contains the ovules or seeds ; the style or slender pj^ g^ 

 part above the ovary ; and the stigma, the more or 



less enlarged upper end of the style. The style may be want- 



