FLOWERS, THEIR STRUCTURE AND KINDS 14! 



which serve the purpose of protecting the essential members con- 

 cerned in pollination and seed production while they are in a 

 young and tender condition, in the bud. 



225. The members, or parts, of the flower are crowded 

 together on a very short portion of the stem. This close asso- 

 ciation of a number of such important parts of a plant into one 

 structure gives a very great importance to the flower in indi- 

 cating the relationships of flowering plants. While there are 

 other parts of flowering plants which are of importance in show- 

 ing relationships, the flower is one of the most important struc- 

 tures in this respect. In addition to the complex structure of 

 the flower already indicated, when we come to compare the 

 flowers of different kinds of plants we find that the members of 

 the flowers vary, not only in the number of the different kinds of 

 members and their form, but in the relation of the kinds of mem- 

 bers among themselves and to each series of members. In the 

 simpler kinds of flowers the members are all separate and dis- 

 tinct, while in the more complex and highly developed ones the 

 members are more or less united. It is important therefore in 

 the study of flowers that we should attempt to determine not 

 only the parts which are present, their position, and relation to 

 each other, their function, the different mechanisms by which 

 the different kinds of flowers perform their functions, but also 

 the significance of the form of the flowers and their arrange- 

 ments on the flower shoot. 



226. The different kinds of members, or parts, of the flower 

 appear to be arranged in whorls, because they are so closely 

 crowded on the stem. In some flowers, the buttercup and some 

 of its relatives, they are believed to be arranged in spirals similar 

 to the arrangement of the leaves, though so crowded that it is 

 difficult to determine. 



Studies of a few flowers are presented here to illustrate their 

 structure, ?s well as the arrangement and relation of their parts. 



