happen to have no measurements at hand with which to make this comparison in the case of our native trees, but from a paper by Mr Charles E. Hall69 I have compiled certain mean values for growth in the climate of Uruguay.
| Jan. | Feb. | Mar. | Apr. | May | June | July | Aug. | Sept. | Oct. | Nov. | Dec. | |
|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Evergreens | ã9ôñ1 | ã8ôñ8 | 8ôñ6 | 8ôñ9 | 7ôñ7 | 5ôñ4 | 4ôñ3 | 6ôñ0 | 9ôñ1 | 11ôñ1 | 10ôñ8 | 10ôñ2 |
| Deciduous trees | 20ôñ3 | 14ôñ6 | 9ôñ0 | 2ôñ3 | 0ôñ8 | 0ôñ3 | 0ôñ7 | 1ôñ3 | 3ôñ5 | ã9ôñ9 | 16ôñ7 | 21ôñ0 |
The measurements taken were those of the girth of the tree, in mm., at three feet from the ground. The evergreens included species of Pinus, Eucalyptus and Acacia; the deciduous trees included Quercus, Populus, Robinia and Melia. I have merely taken mean values for these two groups, and expressed the monthly values as percentages of the mean annual increase. The result (as shewn by Fig. 31) is very much what we might have expected. The growth of the deciduous trees is completely arrested in winter-time, and the arrest is all but complete over {120} a considerable period of time; moreover, during the warm season, the monthly values are regularly graded (apôÙproxôÙiôÙmateôÙly in a sine-curve) with a clear maximum (in the southern hemisphere) about the month