15 



part of the subject one might enlarge upon here, but although this 

 should logically come first, it may, and often will, be studied after 

 one's acquaintance has been made with the fully developed fruit. 



Taking first the fruits whose walls are dry and more or less hard, 

 the so-called dry fruits, we find that some of them open to liberate 

 the seeds — the dehiscent fruits, while others do not open — the 

 indehiscent fruits. Beginning with the latter, the dry indehiscent 

 fruits, a good example is seen in the wild clematis or traveller's joy. 

 As the fruits ripen the styles at the apex of the little fruits grow long 

 and feathery, and finally present the appearance to which the plant 

 owes its name of old man's beard (PI. VI, fig. i). Each of the 

 little fruits is called an achene, and is a superior one-celled, one- 

 seeded fruit, whose wall can be separated from the seed although it 

 wraps it closely round. 



If we wish to get good examples of the fruits of the dandelion, 

 they should be gathered in the condition of that in PI. VI, fig. 2, 

 and then put in water singly. The specimen shown was photo- 

 graphed one morning, and in the evening it had developed into the 

 fine dandelion clock seen in PI. VI, fig. 3. It is very interesting 

 to watch how the globular shape is brought about by the simul- 

 taneous opening of the little parachutes. Of course, this is a good 

 example of a fruit which owes its distribution to the parachute 

 arrangement and the help of the wind. The fruit is somewhat 

 similar to the achene, but differs from it in being inferior (it is 

 crowned by the pappose calyx), and it is bicarpellary in origin, as 

 indicated by the two stigmas of the flower. It is sometimes called a 

 cypsela, but much more frequently and quite erroneously it is called 

 a seed of the dandelion. 



The nut has been developed from an ovary of two or more cells 

 containing one or more ovules in each cell, but the ripe fruit has 

 usually one cell containing a single seed, the other cells and ovules 

 having become abortive. The wall is hard and is surrounded by a 

 cupule or cup, which varies somewhat in its appearance and structure 

 in different plants. In the hazel the cup is somewhat tough and 

 leathery. The acorn is another variety of nut, but the cup is harder 

 and denser than in the previous example. In the beech the cup 

 contains two nuts. Another example is seen in the sweet chestnut. 

 The prickly cup often contains three nuts, but generally we find that 

 one is much more developed than the others. 



We must distinguish the nuts of the sweet chestnut as fruits from 

 the seeds which we shall see later in the horse chestnut. In the 

 sweet chestnut we find the remains of the styles at the apex of the 

 fruits, while in the horse chestnut the large hilum of the seed indicates 

 its morphological value. The sweet chestnut has indehiscent fruits ; 

 it is the cupule which opens to liberate the fruits, and this is very 

 different from the horse chestnut, whose fruit dehisces to liberate 

 the seeds. 



In the hornbeam we may consider the fruit as a nut partly enclosed 



