So SCIENCE PRIMERS. [xxi. 



XXI. THE FRUIT. 

 PERICARP, SEED. 



125. The fruit consists of a covering (seed-vessel, 

 or pericarp) containing one or more ripe seeds, The 

 term should strictly apply to the result of the fertiliza- 

 tion of one pistil," but it is extended to crowded 

 masses^ of fruits belonging to several flowers on one 

 peduncle or branch (mulberry Fig. 58, pine-cone). 

 These are called aggregate fruits, or infructescences, 

 just as the aggregates of flowers are called inflor- 

 escences (Par. 75). Further, various organs of the 

 flower, or inflorescence, when retained on the fruit, 

 are considered parts of the fruit; as the acorn-cup, 

 which is formed of scale-like bracts (Par. 79); the flesh 

 of the apple, hip, and pear, which are all formed of 

 the swollen peduncle ; the strawberry (Fig. 64), which 

 consists of a fleshy receptacle covered with ripe 

 carpels ; and the fig (Fig. 59), which is a hollow fleshy 

 peduncle containing many ripe carpels. 



126. The study of the fruit is more complicated than 

 that of any other organ of the plant, because : i. of 

 its composition, which can only be made out by an 

 examination of the pistil (Sect. XVIII.) ; 2. because 

 many parts visible in the pistil are often suppressed or 

 masked in the fruit ; 3. because the seed is not always 

 as distinguishable from the pericarp as the ovule 

 always is from the ovary ; 4. because accessory organs 

 are so often attached to it or envelope it; 5. because 

 carpels that are free in the pistil may become com- 

 bined in the fruit; 6. because the placentas (Par. no) 



