BY D. MCALPINE. 695 



before spreading out, than in the apple. The nests of strongly- 

 thickened cells or "stone-cells," which occur so plentifully in the 

 ])ear and form the so-called "grit," also occur in the quince, but 

 not in the apple. The want of this additional skeleton in the apple 

 may be correlated with the fibro-vascular system being generally 

 coarser and tougher in texture. 



The vascular system invariably forms a network beneath the 

 skin, with the plume-like branches arising from it; and in the 

 quince, these are particularly noticeable as forming a dense inter- 

 woven mass of delicate down-like material. 



We can now picture to ourselves, in some measure, tlie marvel- 

 lous adjustments necessary to produce the symmetrical, shapely, 

 and healthy pome. The core, at first, is the main portion, in con- 

 nection with which the vascular system is developed. Then the flesh 

 surrounding it enlarges, and the pressure of growth in both flesh 

 and vessels will cause branches from the main vascular system to 

 l^ermeate it. These branches, at the periphery, must form a regu- 

 lar capillary network, so as to ensure a regular and equable supply 

 of nourishment where the greatest and most rapid growth is taking 

 place. If growth is regular and steady, a shapely fruit is pro- 

 duced ; but if it is intermittent, by fits and starts, then the regular 

 formation of the capillary network is interfered with, and at those 

 spots where this occurs, the cells are deprived of their nourisliment 

 and die. 



Tliere are thus two centres, as it were, to which food-material 

 must be steadily directed, the developing seeds of the core, and the 

 rapidly growing cells of the flesh. There must be an equable dis- 

 tribution of nourishment between them, so that there is proportion- 

 ate growth in each, otherwise, the balance would be disturbed. The 

 core reaches maturity first, and then the pulp-cells monopolise and 

 store up material for the ripening process to take place. 



The fruit becomes soft and succulent, while the sweet taste, the 

 aroma, and the delicate flavour are developed. If there has been 

 harmonious working of the different parts, if the different capil- 

 lary networks have been completely formed, and if the food has 

 been supplied in due proportion, the result is the symmetrically 



