CH. XTV] PEAR. 195 



structure of those plants. The wall of the cup-like 

 receptacle shown in fig. 90 must be imagined to be 

 greatly thickened and so much contracted that the 

 opening is almost closed above. If within this, five 

 carpels are placed, a model of the pear flower will have 

 been made. The wall of the receptacle may be recognized 

 by the stamens springing from its rim ; two of the five 

 carpels are seen at 0, each terminating in a style which 

 emerges at the contracted opening of the cup : an ovule 

 is visible in each carpel. It is especially noticeable that 

 the thick fleshy wall of the receptacle is adherent to the 

 carpels, so that a transverse section of the mature fruit 

 shows the seeds lying in five cavities in the flesh, there 

 being no space between the wall of the receptacle and the 

 ovary : nevertheless the ovary wall is distinguishable in 

 the membranous substance known as the core. In the 

 mature fruit divided longitudinally as. shown in fig. 94, 

 the remains of the calyx are seen at the upper end, 

 but the passage through which the styles emerged is 

 practically obliterated. 



In the pear and apple the edible part of the fruit is 

 supplied by the swollen fleshy receptacle, the walls of the 

 ovary being membranous, instead of juicy, as in the 

 gooseberry; or half fleshy, half stony, as in the cherry. 

 The protective function depends on the leathery coating 

 of the seeds. 



There is a good deal of evidence to show that plants 

 are actually distributed by the seeds which have passed 

 through the bodies of animals. The most familiar instance 

 is supplied by the mistleto (Viscum) whose seeds are 



132 



