THE INFLORESCENCE AND THE FLOWER in 



form which produces spores the so-called sporophyte 

 phase of the plant's life history. 



We have pointed out that in the flowering plants two 

 kinds of spore are produced. The little ones resemble 

 the spores of the ferns and mosses ; they are small cells 

 with thick walls, usually spherical in shape. They are 

 liberated from the sporangia in which they are de- 

 veloped and germinate after their removal. The large 

 spores are produced singly in each sporangium and 

 never escape from it. The sporangium is a bulky struc- 

 ture and consequently the spore need not develop the 

 thick wall found on the little spore. 



We have now to see where these spores occur and 

 what is the story of their behaviour. 



In most ferns we saw that the sporangia occur in 

 patches on certain places on the ordinary leaves. In 

 some, however, they are found on very specialised out- 

 growths, generally .spoken of as modified leaves. In the 

 flowering plant the sporangia are usually collected at 

 the end of special shoots which are known as flowers. 

 A special system of the branching is set apart for their 

 production. It may consist of very many branches and 

 may be very complicated, hence it is usually considered 

 separately under the name of the inflorescence. Its 

 ultimate branches are known as flowers, the leaves in 

 whose axils they are found are termed bracts. 



A very common form of the inflorescence is that in 

 which the main axis continues to increase in length and 

 bears a succession of flowers as it grows on, so that the 

 youngest flower is nearest the apex. This corresponds 

 to the indefinite method of vegetative branching. The 

 inflorescence is called a raceme. There are many modi- 

 fications of it on all sides : if the flowers have no stalks 

 it is called a spike; if they all reach the same level 

 through the older stalks growing longer than the younger 

 it is a corymb ; if the axis is so short that all the flowers 



