Study of Sweet-peas. 69 



next exercise. Each pupil should have a peduncle bearing 

 two flowers and a bud ; or, one flower and two buds. 



EXERCISE 38. 



Study of Sweet-peas Continued. Have you ob- 

 served insects visiting sweet-peas ? Were any of them 

 collecting pollen with their hindermost legs? Did those 

 seeking nectar receive any pollen ? Observe again an 

 open flower. Do you know whether the petals have the 

 same position at night as in the daytime ? If the upper 

 petal remains erect in a rain storm could water enter the 

 nectary? Of what use are the two projections at the base 

 of the erect portion of the upper petal ? Remove the upper 

 petal and the side pair. Cause the style to go in and out of 

 the pouch that you may see how it works. Which way do 

 the hairs of the pollen-brush point ? Explain how it works. 

 Only the tip of the style is stigmatic. Take one of the 

 buds. Note that the upper petal encloses all the others. 

 Remove it and the side pair. Is there any loose pollen in 

 the pouch ? Hold it up to the light. Observe that the 

 lower and front edges of the two petals which form the 

 pouch are united from near the base to the tip of the 

 enclosed style. Loosen the pouch at the base and slip it 

 off without injuring the stamens. Count the stamens. 

 With a needle or pin raise the distinct one which is above. 

 The others are united for the whole length of the ovary or 

 two-thirds of their length. Find the nectar at the base of 

 the sheath formed by these united filaments. Do you see 



