110 TRANSACTIONS AND PROCEEDINGS OF THE [Sess. lv. 



Avceks it rises again to 600, but after that declines to about 

 450 for three weeks till August 9th, after which it rapidly 

 falls to the end of the season, which is on the 20th September. 

 Taking fortnightly periods, there is a midsuninier depression 

 of 810, preceded by a fortnight at 11 35, and followed by one 

 at 1050. This period corresponds with the deepest part of 

 the long depression in the Pinaee?e. It is also remarkable 

 that the severe fall of the latter in the last week of May is 

 represented in the deciduous group by an evident check in 

 the weekly rise to the maximum. One member of the 

 deciduous group, however, was exempted from each of these 

 depressions, one of the elms in May, and the cherry in June- 

 July. As the deciduous trees were under observation for 

 only one year, and as the results are not strongly marked, 

 further experiments are necessary before a decided opinion 

 can be expressed as to the progress of their seasonal growth. 



C. Abnormal (?) Deciduous Group, 1890. 



It was not deemed advisable to take the tliree trees in this 

 group along with the other deciduous trees, as, although 

 healthy looking, they grew at a rate much below their average 

 for the previous three years. In the case of the alder and 

 hawthorn the failure was all through the growing season, and 

 the irregularity of their weekly growth is very striking 

 (Table II.). The poplar failed in the first half of the season 

 only. To the end of June it increased only 015 in. instead 

 of O'oO as in the previous year. These trees all flowered 

 profusely, but so did the two elms and the cherry, which 

 maintained their girth-increase unimpaired. 



III. — The relation betaveen Girth -Increase and the 

 Growth of the Buds and Twigs. 



In 1888 a comparison was made between girth-increase 

 and the growth in size of the top shoot of the Pinaceae, 

 ascertained by measuring-rods, which can be fairly accurately 

 done up to a height of 10 or 12 feet. All the trees seemed 

 healthy and vigorous, and were easily measured except the 

 araucaria, which was not very reliable, owing to the rough- 



