BY D. MCALPINE 



693 



portion of the net has been detached ( Fig. 11), and the meshes are 

 shown with the delicate veinlets arising from their boundaries. It 

 is situated about one-eighth of an inch beneath the skin, and 

 forms a continuous layer. 



There is the same elaborate system of vessels, as in the apple and 

 pear; but the plume-like branchlets towards the circumference are 

 apparently much more numerous, and much more delicate. In a 

 relatively large fruit, such as the quince, and one which has been 

 little modified by cultivation, tlie green hypodermal cells of the 

 fruit itself (Fig. 14) would contribute a considerable proportion of 

 the starch for storing up, and consequently the means for conveying 

 it, when converted into sugar, would require to be increased. 



The vascular net-work is likewise present, and having examined 

 this wonderful structure in the three principal pip-fruits or pomes, 

 we are now in a position to show what part it plays in the economy 

 of the fruit. 



This network exists from the earliest stages of the fruit (Fig.lO), 

 and it is similarly developed in connection with the "core" and the 

 "flesh," thus ensuring the harmonious growth of both structures. 



As regards the carpels, the primary vascular bundles give off 

 internal branches passing to the dorsal and ventral surface of each. 

 These dorsal and ventral branches s^^read out over the surface, and 

 unite to form the beautiful network completely enveloping each 

 carpel. 



As regards the flesh, which is the bulkiest part of the pome, the 

 primary bundles give off external branches, which form a vascular 

 net at the zone of greatest growth, just beneath the skin. This net 

 must be continually enlarging its meshes, so as to accommodate 

 itself to the ever-increasing area, until the fruit is finally mature. 

 The boundaries of each mesh give rise to plume-like branches, 

 which permeate and bind together the peripheral layers, like a 

 compact turf knit together by the fibrous roots of grasses. 



The vascular net, both on the carpels and in the flesh, must be 

 undergoing expansion while growth continues, and the question is. 

 How is this done"? It has to be continually readjusted to the 



