428 XXXI. THE FRUIT. DEVELOPMENT OF THE FLOWER. 



of fibrous, in part thickened tissue. The spongy elements, found 

 outside the loculi as well as in the interior of the partitions, easily 

 fall out of union. The fibrous elements, on the other hand, 

 appear pretty firmly connected together. The best view of these 

 latter is obtained in surface view. We separate the segments 

 from one another in the customary way ; the spongy tissue 

 surrounding the loculi is thus torn, the fibrous layer remains, 

 however, as a delicate white sheath around the flesh of the fruit. 

 If we now spread out such a sheath and examine it with a high 

 power, we see it constructed of several layers of fibres, running 

 parallel to the surface of the loculus, and at right angles to its 

 long axis. Between unthickened fibres are scattered others of 

 similar form, thickened and pitted. 



The flesh of the fruit consists of club-shaped sacs, of which 

 it can be readily seen, even macroscopically, that they all arise 

 from the outer side of the loculus. They are here inserted with a 

 narrow base, and, crowded together, fill up the loculus. The 

 larger they are the more deeply they extend into the loculus ; 

 their course is radial, at right angles to the long axis of the 

 loculus. Each individual club shows at its surface to be sur- 

 rounded by a layer of closely united elongated fibrous cells, just 

 as we see them in the partitions of the segments. Interpolated 

 between these cells are single ones, more strongly thickened, and 

 provided with obliquely ascending pits. The interior of the clubs 

 is, however, filled with very large, polygonal, delicate -walled cells, 

 full of sap, in the interior of which are visible spindle-shaped, very 

 narrow, orange-red chromatophores. The central core of tissue, 

 in which the partitions come together, is formed of similar spongy 

 parenchyma to the internal part of the rind. In " quartering " 

 an orange we free, as we see, the contents of the loculi, sur- 

 rounded by the fibrous layer clothing each loculus, which is 

 easily separated from the spongy parenchyma. This fibrous 

 layer can now be very easily separated from the sides of each 

 segment, with more difficulty from its outer surface, because 

 here the sacs of the flesh are joined to the fibrous layer. In the 

 flesh the seeds (" pips") lie embedded in uncertain number. 

 They occupy the inner edge of the sections, their place of inser- 

 tion being turned inwards. In isolating the sections the seeds 

 are separated from the placenta ; usually, however, portions of 

 the inner core of tissue, together with the placentae, cling to the 

 inner edges of the sections. Mucilaginisation of the spermoderm 



