THE GIRTH-INCREASE OF TREES. 77 
AGGREGATE INCREASE IN GIRTH FOR TWENTY YEARS OF 
NINE OTHER SPECIES OF INFERIOR OR DECLINING 
VIGOUR. 
— 
Fiast DECADE, 
1878. | 1879. | 1880. | 1881. | 1882. | 1283. | 1884. | 1885, | 1886, | 1887. 
Tilia europcea (2) .. By Oi a eae sf ere Sa ae, ete’ oe ded ed (! os fle eee ed ee 
Castanea vesca.. 664'T:104] 90) 85-4 110 (80-41-00 +100 |. 851 200-5 75 
Liriodendron tulipifera.. | 1:00 | ‘40 | ‘30 | 65 | 60 | 45 | 65) 55 | ‘To | °65 
Acer Pseudoplatanus ..| ‘50 | '20 15 30 | “40 45 55 | 40 | 354: 20 
Csculus Hippocastanum | ‘75 | ‘60 | ‘35 70 | 10] 30} 20; 05} ‘20 ] 20 
Carpinus Betula .. | 40 | 86 19 55 50; 45} 65) 40 30 | °50 
Quercus rubra = we [2 780 F740. ] 30) = 80.) e280 2 ae 65 | 45 | 55 
Juglans regia = 2 D0 2G 1 00 a 10 16.4 0 46 
Betula alba .. a a Sd Oe es A 00] 10; 00) 10; 00 
Total = _. | 6-20 | 3°75 | 2°25 | 4°80 | 4°15 | 3°70 | 4°35 | 3°45 | 3°80 | 3°40 
Seconp DECADE. 
1888. | 1889. | 1890. | 1891. | 1892, | 1893. | 1894, | 1895. | 1896. 1897. 
Tilia europea =e .. | 30} 65} 95 | 40] 65 | 1°05 80 10 | ‘70 35 
Castanea vesca .. .. | 60 | “75 | 1:00 90 | -90| 40} 80] 45 8 
Liriodendron tulipifera .. | 35 | 40] *80| 60 | 65 | 40 | 75 | 35 | “40 25 
Acer Pseudoplatanus ..| ‘20 | ‘20| ‘30 10. | ‘3 | 26 | ‘lb 15 | °*36 15 
(Esculus Hippocastanum| -36| ‘10| 05 | 00} 25 | 10] 25 | 25 | “30 | 00 
Carpinus Betula .. 1 a 8b oe 1 40 35 | 30} 50) <2 
Quercus rubra 40 30 | ‘50 35 | 45 | 40 | °56 40 | °35 | 2 
Juglans regia .; | 0 | 00] 15 | 00 | S| 2] 2] 15] | 
Betula alba .. 05 | 00| -20 05 | 05 10 10 | 05 15} 00 
Total . a: .. | 255 | 2°75 | 4°45 | 2-30 | 4°05 | 4°00 | 35°60 265 | 335 | 2°20 
The progressive though fluctuating degeneracy in this group 
is very marked. From the standard of 6°20 in 1878 the fall in 
1880, the second severe season, was to 2°25, and the rally in 1881 
was only to 480, an amount which they never again quite 
reached. Their average for the last five years was little above 
3°00, or one-half the standard of 1878. It is probable, therefore, 
