-6- 



along the parkings. 



The species must be one which does not have drooping branches to interfere 

 with the lighting of the street, either natural or artificial, or must stand 

 constant pruning. In special cases where electric wires of any sort occur 

 some concession must be made to them. But the question of surface wiring is 

 a temporary one for the time should be fast coming whan all such wiring will be 

 put under ground. The details which are of concern are chiefly those of the 

 tree and not of the telephone or lighting companies. Furthermore, the head 

 of the tree must be neither too dense or too open; it should be erect and not 

 drooping; and the leaves should keep in good condition until falling. The 

 ideal street should offer a perspective as in Fig. . 



Again the species selected must be relatively free from the attacks of 

 insects and fungi. It would be impossible to find a tree which w- s entirely 

 immune, but there are some trees which are more resistent than others. A case 

 in point would be the hawthorne, which, in the Santa Clara Valley and Bay regions, 

 is infested with scales and aphids, in the excreta of which flourishs the sooty 

 mould fungus which annually disfigures the trees. These conditions are, of 

 course, controllable, but the time, energy and expense entailed make it obvious 

 that the aesthetic value of the Hawthorne does not justify such effort in order 

 to have it on "the street. 



The question of shade is very important in some parts of California and not 

 so much so in others. In spite of the mildness of the climate, wa find ourselves 

 dependent on the sun for our comfort. For this reason alone, evergreen species 

 should be considered with considerable hesitation, especially on streets running 

 east and west. In addition, evergreens hold the moisture and by preventing 

 rapid evaporation bring about bad conditions on the road or highway. But of 

 this question of deciduous versus evergreen species, more later. 



Spacing often spoils a good tree. A case in point is the frequent use of 

 Acacia melanoxylon. This is an excellent tree in many ways. Its natural mode 

 of growth is symetrical and fairly rapid; the scale insects which attack it 



