33 



NATURE-STUDY 



of geraniums, sweet peas, pansies, tomatoes, corn, etc. 

 In this way seed will be formed which, if properly ripened, 

 will produce plants that have the combined or blended char- 

 acteristics of the parents. This is called making hybrids. 



Many choice flowers 

 in greenhouses and 

 gardens and new va- 

 rieties of fruit are 

 thus formed by the 

 cross-pollination of 

 nearly related, but 

 different, plants. 



These pupils are 

 old enough to make 

 a study of the uni- 

 sexual flowers of 

 trees. Begin with 

 the willows and cot- 

 tonwoods. These 

 come out early in 

 the spring before the 



FIG. I29 . Jack-in-the-pulpit. fc^ appean The 



flowers are quite small, and are arranged in long drooping 

 clusters, which are called catkins. On some trees there 

 are only staminate catkins, and on others only pistillate. 

 The staminate flowers consist each of a little scale, under 

 which are borne a number of short stamens. At first 

 the scales are closely overlapping, but as the flowers ma- 

 ture the scales separate, and the stamens with their dust- 

 like pollen appear. This is wafted to the pistillate flowers 

 on other trees. The pistillate flowers similarly consist of 



