444 



THE AM ERIC AX XATURALIST. [Vol. XXXVI I. 



blue with the palate covered with velvety white hairs. The 

 visitors are flies and bees. 



The Orobanchaca? are parasitic plants without chlorophyll, 

 usually colored yellowish or purplish. The flowers also are 

 frequently yellowish or purple. In variety luteum of Aphyljon 

 fasciculatum the whole plant is yellow. Sometimes the flowers 

 are bicolored, yellow or white, and purple. 



The Bignoniaceae, or trumpet-creeper family, occur chiefly in 

 the tropics. Many of the species are bird flowers, one to two 

 inches in length, and crimson, orange or scarlet, as Bigtionia 

 venusta and Tecoma radicans. Common examples of bird 

 flowers in North America are Lobelia cardinalis, (iossypiitm 

 hcrbaccum and Loniccra sanpervirens. The ruby-throated 

 humming-bird, however, visits many flowers fertilized by insects. 

 The Acanthaceas, a large tropical family of some 1800 species, 

 also contains many scarlet bird flowers. 



The order Plantaginales includes but a single family, the 

 IMantaginacea;, or plantain family. The inflorescence is in 

 spikes with small 4-merous flowers, which are mostly greenish 

 or purplish, and are wind-fertilized. They are of special interest 

 because they show the beginnings of adaptations to insect 

 visitors. In one or more species, "we have before us the 

 passage from anemophilous to entomophilous characters, the 

 evolution of an entomophilous from an anemophilous spe- 

 cies." Planta^o mciia possesses a pleasant perfume and red- 

 dish filaments. Muiler distinguishes an anemophilous and an 

 entomophilous form, which differ -lightly in color, the stamens, 

 stigmas, and pollen. Twenty-tour visitors have been collected 

 on the flowers. The limb of the corolla and sometimes the 

 border of the sepals of P. alpina is red. Five insects in the 

 Alps have been collected on this species. According to Knuth, 

 the flowers of I'lantago display a variety of colors; in P. major 

 the corolla is brownish, the filaments white, the anthers red, 

 brown, or sometimes yellow or even white, while in other species 

 yellow, red and violet appear. 



The three orders, Rubiales, Valerianates, and ( "ampanulales, 

 which terminate the Gamopetalae, exhibit many affinities with 

 the families, which stand at the close of the Choripetalous 



