Buds and Stems. 



65 



light to guide it toward its support. The common trumpet 

 creeper, Tecoma radicans, acts in this way. Figure 24 is 

 a drawing from nature showing seedlings which have 

 started at some distance from the wall toward which they 

 have sharply turned ; their leaves, however, are facing the 

 light. As this plant climbs a wall its shoots lie close 

 against it, so that the clinging roots easily get a foothold. 

 But the shoots that are to produce flowers as well as leaves 



Fig. 25. 

 Linaria cymballaria clambering over rocks. After Kerner. 



turn toward the light instead of from it (see Fig. 24), so 

 that the flowers may be easily detected by the insects and 

 humming birds which assist in their cross pollination (see 

 page 170). A no less marvelous example in which the 

 sensibility of the plant involves a perception of its own 

 condition (conscious recognition is of course not meant) is 

 furnished by the behavior of the flower stems of Linaria 

 cymballaria, a clambering plant which fastens itself to 

 walls, etc., by means of suckers. The pedicels bearing 

 newly opened flowers turn outward toward the source of 

 greatest light so that the flowers are noticeable to those 



