118 



TRANSACTIONS AND PROCEEDINGS OF THE [sess. lv. 



Table YI. 



Here the species of AJ/ics are the only ones that seem to 

 follow the law of retardation, but monthli/ intervals are too 

 long to test the point, and this is proved by the facts that 

 my vjcckly observations brought Pinus cxcelsa under the law, 

 although monthly observations seemed to exclude it. 



3. There is some reason to believe that a similar, though 

 much slighter, retardation takes place in deciduous trees, 

 but observations for a single, and exceptionally cold, cloudy, 

 rainy summer are insufficient to establish more than a 

 suspicion, and require contirmation by further experiment. 



4. Trees which are abnormally slow in their girth-increase, 

 even when healthy-looking, are unreliable in such investiga- 

 tions. Under such circumstances conifers seem to tend to 

 fall off in their autumn growth only, and deciduous trees to 

 grow by fits and starts throughout the whole season. 



5. The retardation in girth-increase in conifers is 

 synchronous with the rapid growth of the new top and 

 lateral shoots, and therefore may be due to incapacity on the 

 part of the trees to carry on the two growths in full measure 

 at the same time. 



6. In certain conifers there is a marked increase in girth 

 before the slightest movement in the buds. In others the 

 two processes appear to be synchronous. In most of the 

 deciduous trees observed, the foliage was well developed 

 before girth-increase began, but in elms the two processes 

 appeared to begin at once. 



7. Hence it appears that in some conifers Sprirui foliage is 

 not necessary to girth-increase, although the old foliage may 

 be. And in some deciduous trees (elms) girth-increase 

 apparently begins williout the aid of foliage at all, altliough 



