256 PRUNING. 



or stem, and thereby impart to the one what was taken 

 from the other. 



In the case of a tree growing up with a forked or 

 double stem, one of them is cut away, for the simple 

 reason that, if allowed to grow in that form, the future 

 tree would be less than half the value it would other- 

 wise be with a single stem or trunk. 



This, however, is not generally regarded as the prin- 

 cipal object gained by cutting away the twin stem; for 

 the popular belief is that if the twin stems are each 

 annually gaining 2 inches in girth, if one of the two 

 is cut away, the one left will not, as formerly, grow 

 only at the rate of 2 inches annually, but 4 inches. 

 This theory, though bearing the semblance of truth, 

 is decidedly a false one ; for it will be found by any 

 one who may choose to examine the structure of the 

 wood, years after the operation has taken place, that 

 the layers or zones in the stem had not increased as 

 anticipated, but in all likelihood had rather decreased. 

 Some sections of wood in our possession, cut for the 

 purpose of examining their structures, show one gen- 

 eral, though not uniform, result. Some of them indi- 

 cate a considerable falling off in the thickness of the 

 layers, beginning with the first season's growth ; in 

 others the decrease is not so visible till the second 

 year ; but in all the sections the third year's layer is 

 somewhat thinner than the one produced the season in 

 which the operation was made. 



How and by what means, then, is the stem ever to 

 be increased in thickness if it thus decreases as above 

 described ? It increases by a new and different pro- 

 cess of growth altogether, in the following manner : 

 Soon after the twin stems have been separated, the 

 bark of the remaining one begins to show little risings 



