no BOTANY 



adventitious roots and so grow into a plant. The power 

 of putting out adventitious roots is often used by plants 

 for this purpose. Other familiar examples are afforded 

 by the runners of the strawberry, the suckers of the 

 raspberry, the stolons of the gooseberry and other plants. 



The runner is a lateral branch which grows along the 

 surface of the ground and puts out adventitious roots 

 at its nodes. In the case of the strawberry each runner 

 usually has two nodes, one terminal and one half way 

 along its length. Two new plants arise on each in con- 

 sequence, and when they are established the internodes 

 connecting them with the parent die. 



The stolon is much like the runner ; arising as a lateral 

 branch above the ground it bends down and on reaching 

 the soil it puts out adventitious roots and becomes 

 detached from the parent. The sucker arises from the 

 underground portion of the stem and growing horizon- 

 tally for a time ultimately turns upwards and emerges 

 into the air becoming then detached as in other cases. 



These methods are purely vegetative and do not 

 involve the production of any form of specialised repro- 

 ductive cell. 



CHAPTER XV 



THE INFLORESCENCE AND THE FLOWER 



As we traced the development of the reproductive 

 organs from the seaweeds upwards we found that two 

 special kinds have become constant, the ova and 

 sperms on the one hand and the spores on the other. 

 We also learned that the plant form which produces the 

 spores has become the conspicuous plant, with its roots, 

 stems, and leaves ; while those which give rise to the ova 

 and sperms have dwindled away in dimensions till they 

 no longer have an existence apart from the spore itself. 

 We will study first the reproductive processes of the 



