186 STUDY OF COMMON PLANTS. 



I. Describe first the radical leaves. Compare specimens 

 and see whether the same description will answer for all 

 of them. 



II. Examine the cauline leaves of a number of different 

 individuals and note the various forms. 



III. Are there any means of protection? 



Note. — Do not answer the question hastily. Hairs on delicate plants 

 sometimes protect their tissues against cold, sometimes against small, 

 soft-bodied animals that might devour them or climb up to the flowers 

 and steal the nectar, and again, the presence of acrid juice may render 

 them distasteful to grazing animals. See, if you can, whether this plant 

 is protected ia any or all of these ways. 



Flower. 



Study first the plan of the flower. Are all the parts 

 present? Is it a " regular " flower ? Has any consolida- 

 tion of parts taken place, or are they all free and distinct ? 

 Describe by a single word the insertion of the floral en- 

 velopes. 



Next, examine and describe in detail the successive 

 whorls. 



I. Calyx. How many sepals are there? Is this num- 

 ber constant? Describe their shape, color, and surface. 

 How does their position on the flower bud correspond with 

 that taken when the flowers are fully expanded ? From 

 its earlier condition do you infer anything as to the func- 

 tion of the calyx ? 



II. Corolla. Does the number of petals correspond 

 with the number of sepals ? Remove two or three and 

 examine them under a lens. Draw one in outline, taking 

 care to represent the little scale near the point of insertion. 



Examine the scale carefully. Lift up the free edge 

 with the point of a needle. Frequently a small drop of 



