ORGANS OF REPEODUCTION, 207 



Fig. 420, Fig. 421. 



Fig, 419. 



Fig. 419. Flower of "Wallflower (Cheiranthus Cheiri). c. Calyx composed of 

 parts called sepals, the two lateral of which are prolonged at the base 

 into a little sac, and hence are said to be gibbous. p,p. Petals, of which 

 there are four arranged in a cruciform manner, the whole forming the 



corolla, e. Summit of the stamens, which enclose the pistil. Fig. 



420. Flower of Wallflower with the calyx and corolla removed, in order 

 to show the essential organs of reproduction, r. Thalamus, g/. Glands. 

 ec, ec. Stamens, of which there are six, four long and two short, the 

 whole forming the andrcEcium. sti. Stigma, the summit of the gynoe- 



cium or pistil. Fig. 421. One of the stamens of the Wallflower. /. 



Filament, a. Anther, j'- PoUen, which is being discharged from a slit 

 in the anther. 



for their protection. The essential organs are called the Aiidrce- 

 cium, (Jig. 420, ec), and Gyncecium or Pistil {fig. 420, sti). 

 The floral envelopes are termed Calyx {fig. 419, c), and Corolla 

 {fig. 419,^). The extremity of the peduncle or pedicel upon 



Fig. 422. Flower of a species of S<iuill {Scilla italica). The parts compos- 

 ing the floral envelopes here closely resemble each other, and form 



collectively a perianth. Fig. 423. Flower of Goosefoot {Chenopodium), 



with only one floral envelope. 



