THE (GERANIUM FAMILY. 183 



III. Study the flower itself with reference to the same 

 question. Compare the color of different specimens and 

 varieties. Is there anything to indicate to a visiting insect 

 the way to the nectar ? Find the nectar-tube and explore 

 with a bristle. 



NOTE. Some specimens have a nectar-tube united with the pedicel 

 and easily recognizable on the outside, either by its color or by its form- 

 ing a longitudinal ridge. In others it is not readily found. Even flowers 

 of the same inflorescence differ in this respect. 



IV. Compare the stigmas of older flowers with those in 

 which the anthers are just shedding their pollen. Are the 

 flowers proterandrous or proterogynous ? 1 



V. Study the structure of the mature fruit, and ascer- 

 tain how the seeds are disseminated. 



NOTE. The geranium lends itself readily to experiments in cross- 

 fertilization, and the student who has opportunity is advised to cross two 

 widely different varieties and compare the growth and vigor of the crossed 

 seedlings with that of seedlings derived from self-fertilized flowers. 

 Read the chapter on Pollination in Professor L. H. Bailey's Nursery Book. 



RELATIONSHIP. 



I. Compare the plant just studied with the wild cranes- 

 bill, noting points of agreement and difference. Give 

 special attention to the flowers of the two genera, examin- 

 ing them whorl by whorl, until you are satisfied regarding 

 their differences. Record these in detail. Refer in this 

 connection to Miiller's 2 or Lubbock's 3 account of various 

 species of Geranium. 



1 Cf. Darwin, Cross- and Self-fertilization in the Vegetable Kingdom, 

 p. 142. 



2 Fertilization of Flowers, pp. 149-158. 



8 British Wild Flowers in Eelation to Insects, pp. 43, 44, 72-74. 



