THE FLOWER. 



63 



from one to another. In the KaJmia blossom the anthers 

 of the ten stamens are lodged in cavities in the co- 

 rolla, and the filaments are curved 

 backwards as the flower expands 

 (Fig. 146). Bumble-bees, hovering 

 over the flowers, 'searching for nec- 

 tar, liberate the stamens by occa- 

 sional contact, which, in springing back straight, discharge 

 the pollen from pores at the top of the anthers (Fig. 147). 

 Some of the pollen grains which strike 

 the under side of the bumble-bee and 

 adhere to it, will, when the next flower 

 is approached, be deposited on its 

 stigma, thus bringing about cross-fer- 

 tilization. 



146 147 8o. The most varied and wonderful 



contrivances for cross-fertilization are found in the family 

 of Orchids (Fig. 148). The stamens are generally reduced 

 to one, and this is united in a column 

 with the pistil, indicated by the term 

 gynandrous (Gr. guna, pistil ; andres, 

 stamens). The pollen in each anther- 

 cell is united into a mass, and furnished 

 with a little stem or caudicle, which has 

 a very viscid disk (Fig. 148, III, IV, d). 

 These two disks are so placed that 

 when an insect visits the flower, and 

 thrusts its proboscis into the spur for 

 the nectar (as shown by the arrow. Fig. i4« 



Fig. 144. The coiled tip of the keel of a Bean-flower. Fig. 145. The terminal 

 portion of the style of the same flower. Fig. 146. Flower of Kalmia lati/olia. 

 Fig. 147. One of its stamens discharging poUen, slightly magnified. Fig. 14S. 

 Orchid flower: /, flower entire; //, some parts removed; /// and IV, poUinia 

 attached to a lead pencil ; d, disk ; /, poUinia ; st^ stigma ; AS., anther or poUen- 

 sac; c/, caudicle; Illasii IV, slighdy magnified. 



