THE DEFLECTED AXIS OF QBOWTH 7 



they are largest and strongest, and are most ex- 

 posed to sunlight. These failing, the opportunity 

 will fall to one or both of c c ; and these fail- 

 ing, the long-waiting dormant buds may find their 

 chance to grow. In other words, there are more 

 biids upon any twig than are needed, but there 

 is, thereby, a provision against emergencies. 



Suggestions. — The pupil should give himself some practice in 

 determining or locating the rings marking the annual lengths of 

 growth. A good way to do this is to choose some tree of known 

 age (as a fruit tree or shade tree which has been planted but a 

 few years), and endeavor to account for all the years' growths. 

 He should also endeavor to find out how long the dormant buds may 

 live upon any tree. He should attempt to determine if it is true 

 that a moderate growth (so long as the tree remains healthy) 

 tends to make the tree bear. Those persons who have access to 

 vineyards should determine whether the most prolific canes are those 

 of medium size and which do not run off to great lengths on the 

 wires. Examine orchards for this purpose. Many pupils have 

 heard that driving nails into trees tends to make them bear, and 

 the result may have been attributed to some influence which the 

 iron is assumed to exert upon the plant ; but if it is true 

 that such practice induces fruitfulness, the pupil may be able 

 to suggest an explanation of it. Let the pupil also determine 

 whether dormant buds ever grow when the branch is injured 

 above them . 



III. THE DEFLECTED AXIS OF GROWTH 



10. It is evident, from the foregoing observa- 

 tions, that the twig in Fig. 3 cannot continue its 

 growth in a straight or continuous line. Fig. 4 



