374 TH E FRUIT 



(5) Draw a single fruit of Dandelion (Taraxacum), showing 

 the stalked pappus surmounting the one-seeded, dry indehiscent 

 ovary. 



(6) Draw the fruit of sycamore (Acer], consisting of two dry 

 one-seeded carpels. The pericarp of each has grown out in the 

 flower to form a long curved wing. Note that the two carpels 

 easily separate. Dissect one of the seeds, and note the thin 

 testa and the green coiled embryo with long strap-shaped cotyledons. 



Examine the flower of the sycamore and note the developing 

 wings of the ovary, and that each carpel originally contained two 

 ovules. 



Succulent Fruits. 



(7) In the young cherry (Prunus) note the suture (joined margins) 

 of the single carpel, the scar where the style has fallen off, and the 

 flattened disc-like (once basin-shaped) receptacle. Cut a longi- 

 tudinal section, and distinguish the three layers of the pericarp 

 (skin, flesh and stone). In the young seed distinguish the testa 

 nucellus and gelatinous endosperm. Look for the young embryo 

 at one end. 



Compare the ripe cherry. Break the stone and dissect the 

 seed (kernel). The embryo with two cotyledons now occupies 

 the whole space. 



(8) Draw a median longitudinal section of an Apple or Pear 

 flower (Pyrus) from which the petals have fallen and in which 

 the receptacle is distinctly swollen. Note the tubular receptacle, 

 with the sepals attached to its rim, and the remains of the stamens 

 just inside it. The ovaries of the carpels are buried at the base 

 of the tube, and the styles pass up through the centre. 



(9) Draw transverse and longitudinal sections of a partly 

 grown apple or pear (about three-quarters of an inch in diameter) 

 showing the relation of the carpels (core) to the fleshy receptacle. 



(10) Draw similar sections of a ripe apple or pear, identifying 

 the structures visible with those seen in the earlier stages. Note 

 the withered styles still lying in the central tube, the remains 

 of the stamen still often present within the sepals : the vascular 

 cylinder running from the top of the stalk to the base of the carpels 

 and its continuation through the central column serving the 

 placentae ; also the bundles running through the flesh of the 

 receptacle. 



