Tree Measurements at San Jorge, Uruguay. 463 



each other, exactly the same ground and conditions. Planted 

 in 1880, in January 1890 they were ten and a half years' 

 old. The two Paraisos are on the same ground and level, 

 perhaps 15 yards apart; they were planted in 1881, not as 

 seedlings, but as plants that had come up from roots of older 

 trees, and might be called each ten and a half years' old. 

 The two Eobinias are on the same ground and level, 20 yards 

 apart ; they were planted in 1880, and, like the Paraisos. 

 were young rooted plants from older trees, and may be called 

 eleven and a half years' old. The two oaks are on the same 

 ground and level, 15 yards apart. I hclieve the acorns were 

 sown in 1878 ; this would make them eleven and a half years' 

 old. The two poplars are only 2 yards apart ; they are not 

 qviite the same age, and I cannot make a guess at their age, 

 being shoots that have grown up where other trees had been 

 felled. The two gum trees are on the same slope of ground, 

 about 50 yards apart, and are eight and a half years' old from 

 seed, January 1890. Whilst making these estimates of 

 ages, I will include the cottonwood, planted in 1882. As 

 this must have been from a cutting, I daresay it was nine 

 and a half years' old, January 1890 ; and the Acer I cannot 

 make a good guess at, but believe I obtained the seed in 

 1874 or 1875. It may thus be fifteen or sixteen years' old. 



I have represented in Plate V. the curves taken by the 

 monthly-growth figures for each of these five years, and for 

 eight classes of trees, the average of two trees of each species 

 being taken ; and Plate VI. shows the average growth- 

 curves for the whole term of five years for the above sixteen 

 trees, adding in also the five-year average growth-curve for 

 eight evergreens and for eight deciduous trees. The numerals 

 at the ends of all curves signify the actual number of milli- 

 metres of growth for each class, by their averages of two or 

 of eight. Unfortunately, the ruling of the paper on which I 

 have drawn these diagrams is not correct, or the diagrams as 

 well as measurements would be in millimetres. The error 

 of the ruling is about 4 per cent. ; there should be one 

 hundred lines in the space occupied by ninety-six lines. 



I note on each yearly diagram the mean temperature for 

 each year referred to, also the average monthly sunshine 

 hours, also the average monthly rainfall in inches. I do 

 not enter into the question of the correlation of weather and 



