ANTHOPHYTA. 271 



large-flowered species of Catasetnm, native of South 

 America. The flowers are diclinous, i.e., the pollen and 

 the ovules are produced in different flowers. The column 

 of the staminate flower is furnished with a pair of slender 

 horns, one or both of which are sensitive. The pollen- 

 masses are curved and in a state of tension, like a curved 

 ■whalebone spring. Now, when an insect alights on the lip 

 of the flower and comes in contact with one of the sensitive 

 horns, the pollen-mass is instantly set free with a jerk suf- 

 ficient to throw it nearly a metre, and in such a direction 

 as to strike and adhere to the head .of the insect. "When 

 the insect visits a pistillate flower, the pollen-mass is in 

 the proper position to be brought in contact with the stigma, 

 thus effecting pollination. 



514. Much might be written about these truly wonderful 

 plants, but what has been said must suffice to call the at- 

 tention of the student to them. Our native species will 

 well repay a careful examination, while the exotic ones, of 

 which hundreds are now grown in conservatories, show a 

 greater variety in form and color of flower than can be 

 found in any other family of plants. The student may 

 profitably read in this connection Mr. Darwin's work, 

 "The Various Contrivances by which Orchids are Fertil- 

 ized by Insects." 



515. The Monocotyledons include many of our finest 

 ornamental plants. Thus some of the grasses and sedges 

 are grown for the beauty of their foliage and flower-clusters, 

 and many aroids find places in greenhouses, one of the 

 most common being the so-called Calla-lily from South 

 Africa. In the Lilies, however, we find" the greatest num- 

 ber of plants grown for the beauty and attractiveness of 

 their flowers, possibly excepting the Orchids. Of the 



