208 APPLIED BIOLOGY 



plants, in concaved object-slides containing 5, 10 or 15 per cent of 

 white sugar in water (sugar-solution, or syrup). The slides should 

 be kept covered to prevent evaporation. Examine from time to time 

 with the low power of the microscope. It is well to use several kinds 

 of pollen and various strengths of syrup, for the grains do not all 

 germinate in the same strength of sugar-solution. Sometimes it is 

 possible to find pollen-grains beginning to germinate on the sticky 

 stigmas of flowers. 



204. Introductory Study of Flowers. The foregoing 

 account is intended to be merely an introduction to the study 

 of flowers. Their forms are so numerous that only brief 

 interpretation of some of the most common modifications 

 can be attempted in a year's course in biology; and so 

 the authors have selected for study the materials which 

 are most likely to be interesting and useful to general 

 readers. 



Those who are especially interested in the forms and adap- 

 tations of flowers should read the accounts in the standard 

 textbooks of botany by Coulter, Bergen, Atkinson, Bailey, 

 Gray ; and then perhaps such famous books as Darwin's 

 "Cross- and Self-fertilization in the Vegetable Kingdom," and 

 the Chapters on flowers in Kerner's " Natural History of 

 Plants." 



205. Flower-clusters : Inflorescence. In many small 

 plants there is only one flower, and in others the few flowers 

 appear singly in the axils of ordinary foliage leaves. But 

 in the great majority of the common seed-plants the tend- 

 ency is to produce a number of flowers near together in 

 groups or clusters. The term inflorescence refers to such 

 flower-clusters. Fig. 66, A-G illustrates some of the most 

 common arrangements. The main lines in each of these 

 figures represent the main flower-stalk (peduncle), and the 

 branch lines show the position of the individual flower-stalks 

 (pedicels). If time allows special study of flower-clusters, 

 the textbooks of botany by Gray, Bergen, or others should be 

 consulted. 



