MANUAI, OP NATURE STUDY. 145 



In the spring time collect spring beauty, mus- 

 tard of any species, hepatica, buttercup, marsh 

 marigold, wind flower and dandelion, or almost any 

 spring flower, and examine the stamens as to 

 whether the anthers are borne upon long, slender 

 filaments, or are they without filaments, i. e., anth- 

 ers sessile? Does the anther rest upon the tip of 

 the filament, or does the filament adhere to the 

 anther along its entire length ? Notice particu- 

 larly the position of anther in relation to stigma. 

 What sort of opening has the anther in each case ? 

 Discuss the advantages and disadvantages of each 

 opening and each position in relation to fertili- 

 zation. 



Now notice the stickiness and heaviness of the 

 pollen as compared with the light and dry pollen 

 of corn and ragweed in autumn. What conclus- 

 ions do you reach as to method of fertilization 

 amongst these spring flowers ? It must be remem- 

 bered that some flowers do not open until fertiliza- 

 tion has taken place. For example, many species 

 of violet bear closed inconspicuous flowers, and 

 these produce the greater part of the seed. Self- 

 fertilization in such cases is the only method. See 

 Darwin's Cross and Self-Fertilization in the Vege- 

 table Kingdom ; also Geddes & Thomson's Evolu- 

 tion of Sex. 



Besides the flowers just mentioned, most of 



