236 STUDY OF COMMON PLANTS. 



hairs. Which way are the latter directed? What 



do you infer as to their use ? 

 5. Structural features of the leaves. Describe their 



form and venation. With a good lens examine 



closely the surface and margin. Are they smooth 



or rough ? 

 II. Study the plant throughout with reference to its 

 various means of protection and their efficiency. 



Inflorescence. 



I. The flowers are in small axillary clusters. How 

 many in each group ? In what order do they open ? Is 

 this order constant? Classify the inflorescence, giving its 

 appropriate name.^ 



II. Are there any arrangements, in addition to those 

 already noticed, for the protection of the flower? 



Flower. 



I. Study critically the plan of the flower. How many 

 calyx-teeth are there ? How many lobes of the corolla ? 



Remove the corolla with a pair of fine forceps, and lay 

 it open by making a longitudinal slit its entire length, 

 passing through the middle of the lower lip. Fasten it 

 on a flat piece of cork with needles, so as to fully expose 

 the stamens, and examine under a dissecting microscope. 

 One of the stamens has been suppressed. Which ? Notice 

 the insertion of the style, the peculiar form of the ovary, 

 and the nectary surrounding its base. 



II. Taking flowers of different ages, observe the fruit 

 in its various stages of development. How many carpels 

 are there ? ^ 



1 Cf. Gray, Structural Botany, p. 151. 



2 Cf. Gray, Structural Botany, p. 296 ; Luerssen, Botanik, p. 1014. 



