On the Cultivation of the White Guava. 503 



of originating, in the same ratio, one thousand, and so on, as 

 long as force of sap towards new formations is undiminished." 

 — N. 



All shoots under half an inch in diameter, cut from the 

 side of a stem before midsummer, will generally heal over the 

 same season. Terminal wounds made by shortening will not 

 heal over till a shoot has been produced, the base of which will 

 cover the wound. 



The fruit-bearing shoots of all trees, in a natural state, are 

 chiefly such as are lateral, while the wood of the tree is chiefly 

 increased by the vertical shoots ; hence some modification of 

 lateral training will, in almost every case, be found preferable to 

 training vertically. Lateral roots are also those which con- 

 tribute most to fruit-bearing wood ; and tap or deep-growing 

 roots to upright and barren wood. All restraint imposed on 

 trees, whether by training, root-pruning, or ringing the branches, 

 if not followed up by art, will speedily end in disfiguring the 

 tree and rendering it unfruitful, till it has assumed its natural 

 form and habit of growth ; and, if the tree should be of a species 

 so tender as not to ripen fruit in its natural form as a standard, 

 it will, by assuming that form, have become useless as a fruit 

 tree. In the case of all trees in a state of culture, and more 

 especially such as grow in soil the surface of which is heated 

 more than that of the general surface of the locality, as is the 

 case of a border exposed to the reverberation of the sun's rays 

 in front of a south wall, artificial supplies of water are necessary 

 at particular seasons ; and water, therefore, must be considered as 

 much an element of culture as manure. All the diseases of fruit 

 trees cannot be effectually prevented or cured by judicious cul- 

 ture, but most of them may; and all insects which live on the 

 surface of trees may be destroyed or subdued by abundant 

 washings with clear water by the syringe or engine. All fruit- 

 bearing plants (and indeed all others) grown in pots ought to 

 be potted in soil which has not been sifted, and which, if not 

 sufficiently coarse to keep it so open as to receive water freely, 

 should be mixed with fragments of wood, bones, and stone, for 

 that purpose, for supplying manure, and for retaining moisture. 



Art. IV. On the Cultivation of the White Guava (Vsidium py- 

 riferum L.). By Edward Otto. 



(From the Garten Zeitung.) 



The well known tree Psidium pyriferum is but rarely met with 

 in our gardens, although it may be cultivated without much 

 difficulty, if it is allowed sufficient space. 



K k 4 



