CLASSIFICATION OF FRUITS. 89 



we sometimes see the different carpels separate and fall singly 

 then remain closed, or open in the same way as the simple fruits; 

 sometimes also "the back of each cell is torn without the carpels 

 being separated. 



The differences that we have pointed out in the conformation 

 of fruits and the principal variations of form which they present, 

 have led botanists to class them as follows : 



CLASSIFICATION OF FRUITS. 



20. All fruits are included in three classes. 



21. The first CLASS is composed of the SIMPLE or APOCARPOUS 

 fruits, formed of a single carpel or of several free carpels. 



The first division of this class includes what are termed dry 

 fruits, having a thin pericarp and being but slightly furnished 

 with juices, and generally contain only a small number of seeds. 



22. This division contains two varieties ; the first are the in- 

 dehiscent, simple fruits: under this head we have the three fol- 

 lowing forms : 



Caryopsis. Fruit monospermatic (from the Greek, monos, 

 single, and sperma, seed, having one seed) and indehiscent, the 

 pericarp of which is very thin, and intimately connected with the 

 seed, as wheat, barley, rice, oats, &c. 



Akene or achenium (from the Greek, , without, and chainb, 

 I gape). Fruit monospermatic and indehiscent, the pericarp of 

 which is distinct from the proper covering of the seed, as in 

 hemp, sunflower, &c. 



Gland or nut. Fruit unilocular (from the Latin, unus, one, 

 and loculus, partition, seed-vessel not separated into cells) and 

 therefore monospermatic, from the constant abortion of all the 

 ovules except one ;* the coriaceous or woody pericarp of this one 

 presents at its summit vestiges of the limb of the calyx, and is 

 enclosed, either partly or entirely, in a kind of involucrum called 

 cupule, as in the oak. 



23. The second variety of the first division of the first class 

 contains the three following dehiscent fruits : 



* If we regarded the carpels which constantly abort in glands, ache- 

 mums, &c., we must place these in the class of compound fruits ; but most 

 botanists place them here, because, at maturity, they are essentially com 

 posed of a single carpel. 



20. How are fruits classified ? 



21. What are the general characters of fruits of the first class? 



22. What is a caryopsis ? What is an achenium ? What is a gland or 

 nut? 



23. What is a follicula ? What is a legume ? What is a lomentum ? 



17* 



