THE ORGANIZATION OF THE PLANT 



85 



each consisting of a single carpel. In the blackberry each 

 small pistil becomes fleshy and the receptacle serves merely 

 to hold them together. The raspberry is somewhat like the 

 blackberry, but when ripe the pistils separate from the recep- 

 tacle. A few fruits, such as the mulberry, pineapple, and 

 osage orange, are the 

 product of several 

 flowers and are called 

 compound fruits. In 

 the pineapple each 

 " eye " represents a 

 separate flower. 



The object of the 

 plant in producing 

 flowers and fruits is, 

 of course, the contin- 

 uation of the species 

 by the formation of 

 seeds. Many plants 

 too tender to en- 

 dure great cold or 

 drought are able to 

 form seeds that can 

 do so, and thus the 

 life of the species is 

 carried over the un- 

 favorable season. In 

 addition, seeds may 

 multiply and distribute the plants as well. The fruit is de- 

 signed to protect the developing seeds and to aid in distribut- 

 ing them when mature. In some the fruit becomes sweet 

 and juicy, to attract birds and mammals ; in others it forms 

 winglike sails, by means of which the seeds are carried long 

 distances by the wind ; in still others it develops hooks that 



FIG. 75. Seeds modified for wind distribution 



A, buttomvood; B, cat-tail; C, trumpet creeper; 

 ]), ratalpa; E, dandelion; F, clematis; G, olean- 

 der ; //, actiuomeris ; /, anemone ; ./, milkweed 



