532 Pri?iciples of Gardening 



fructification. The Onagrariae develope round an equally long 

 axis a whorl of many such fruits ; the union of these forms the 

 fruit-cluster (Fruchtknoten), which is covered by the calyx above 

 it. The sides of the fruit-leaves bent inwards, thus becoming 

 pressed closer to each other, grow together and form the par- 

 titions ; and, as the cylindrical leaves of the calyx alternate 

 with the fruit-leaves, the individual fruit cannot escape out of 

 this overgrowth, in order, as their formation required, to burst 

 open at the seam in the axis ; but this takes place where the 

 leaves of the enclosing calyx have grown together, and, there- 

 fore, on the middle rib of the fruit-leaves. This formation is 

 very perceptible in the seed-vessels of the ffinotherae. I have 

 also observed, in the beginning of spring, in the seed-vessels of 

 the Philadelphus which had remained on the tree during the 

 winter, and in which the calyx was partly destroyed by the 

 weather, a degenerating into single seed-vessels. In the same 

 manner, with a whorl of three seeds round a very slender fruit- 

 axis, which, apparently, only consists of the placenta, and ac- 

 cordingly, in the regular growth of the fruit, remains attached 

 to the seed, are formed the Zyiliaceae with upper, and the /rideae 

 with under, fruit-clusters. By the growing together of the sides 

 of the fruit-leaves, the fruit of these plants represents a tripartite 

 capsule. If the parts which grow together, and cause the single 

 compartments of the fruit, are fragile, the fruit separates when it 

 is ripe, and they burst open at their axis ; but, if firm, they remain 

 united, and open at the midrib. 



The jEuphorbmc^"^ also produce, round a more distinct fruit- 

 axis, a whorl of three one- or two-seeded fruits ; and, lastly, the 

 Umbelliferse, only two opposite to each other, which are one- 

 seeded, and also covered by the calyx. 



h. The edges of the fruit-leaves growing in a whorl round the 

 fruit-axis do not bend towards the fruit-axis, but grow together 

 sideways, and not with their corresponding bundle of vessels. 

 The fruit-axis, therefore, rises in the hollow of the fruit-cluster 

 thus formed, ends under its point, and only the bundle of vessels 

 attached passes over into the stalk. In this manner is formed 

 the fruit of the Caryophyllese. In the Polemoniaceae, the placenta 

 is extended into three elongated angles, which are formed from 

 the pith, and which run towards the midrib of the fruit-leaves, 

 but which they, however, do not always reach (a similar forma- 

 tion also takes place in several species of Malvaceae, between 

 the single fruits on the fruit-axis, as well as on the base of the 

 fruit-cavity of several of the Caryophylleae) ; the placentae are 

 situated in the angles on the central column. 



2. The fruit-axis is no longer undivided, but separates into 

 as many parts as there are bundles of fibres, and doubles the 

 number of placentae and fruit-leaves, or only of placentse; and 



