104: THE SECOND BOOK OF BOTANY. 



When fruit is formed from the pistil alone, the 

 wall of the ovary is called a pericarp (from peri, 

 around). 



Gather specimens of every kind of fruit that 

 grows within reach. In late summer or early au- 

 tumn, the fruit of garden, field, and forest, if care- 

 fully collected, will give you a large and various as- 

 sortment. For example : you may have at the same 

 time cucumbers, melons, beans, peas, grapes, apples, 

 pears, elder and pokeweed berries, chestnuts, wal- 

 nuts, pumpkins, etc., and the less conspicuous seed- 

 vessels of mullein, Saint- John's- wort, lettuce, radish, 

 cabbage, etc., etc. Earlier in the season the list will 

 be different, and it will vary somewhat with the lo- 

 cality, but, wherever collected, and whatever its com- 

 ponents, be sure to gather every kind that can be had. 



Look over your collection, and separate the supe- 

 rior from the inferior fruits. Observe the structure 

 of those formed from inferior pistils, and point out 

 the pericarp in those formed from superior pistils. 



Preserve, for further study, the specimens you 

 have gathered. 



EXERCISE XXXVII. 

 Farts of the Pericarp. 



EPICARP. When the walls of a pericarp are formed 

 of two or more layers of different texture, as in the 

 peach, plum, or cherry, the outer one (the skin, in 

 the case of these fruits) is called the epicarp. 



ENDOCARP. The stony case around the seed of the 



