316 TRANSACTIONS AND PllOCEEDINGS OF [Sess. i.vr. 



September. At the same time, it is possible that the 

 flifl'erence is due, not so much to the growth being sliorter in 

 point of time in April, as to its being slower. 



In my older group the conditions are the reverse, tlie 

 recorded April increase being considerably greater than that 

 of September, but for various reasons the results are much 

 less reliable. 



Instead of the awkward terms " first and second half- 

 season's increase" " spring and autumn increase " might have 

 been adopted, but this would be misleading, as, after all, the 

 main growth is in summer. 



My earlier observations on older trees of eleven Deciduous 

 species showed that some tended to increase in girth mainly 

 in the first half-season, others in the second. In the new 

 group, seven of these species and eleven new ones are in- 

 cluded, and the results for the whole twenty-two are given 

 in Table VI,, in the order of greatest growth in the first 

 half-season. As a proof that this dillerence in the period 

 of greatest growth is a true characteristic of species, a 

 glance over the Table shows that, as a rule, trees of the 

 same species are near each other. Thus it is remark- 

 able, among fifty-eight trees, to find the only two Horse 

 Chestnuts standing together; also the only two young 

 Birches and Limes; and two of the three Turkish Oaks; 

 while two of the five Sycamores are together, separated 

 by only one tree of a different species from two others 

 of their own species, the fifth being not far off. The 

 three Ashes are also separated by only three other trees. 

 Or — to take the species with the largest number of 

 examples — of eleven Beeches of very different ages, four 

 are together, and four more are within thirteen ])laces of 

 them. Other less-marked examples, which nevertheless 

 show the tendency, are the only two Elms, within ten 

 places of each other, and two of the three Hungary Oaks 

 within seven, all three being within eighteen. Taking tlie 

 liriiish Oaks, only one of the five is found among the first 

 thirty-six trees, the other four being among the next seven- 

 teen. Of the thirteen Oaks of various species, only four are 

 in the first thirty-six trees, and none higher than the 

 seventeenth place, and nine are among the next seventeen. 

 L'<;niaikable exceptions no doubt occur; the two young 



