264 



Dr Christison on the 



b 



seasons on the girth-increase were only noticeable in 1879, 

 and that to but a slight degree. 1883 and 1887 were also 

 years of depression, but not to a marked extent. 



Ai'aucaria imhricata. 



The great frost of 1860, which killed the older Araucarias 

 in the Botanic Garden, did not leave Nos. 34 and 35, then 

 quite young, unscathed. They lost their lower branches ; 

 and if we may judge from the appearance of the Craigiehall 

 tree, it had suffered in the same manner. Otherwise they 

 all appeared healthy enough at the beginning of the decen- 

 nial period ; but No. 34 gradually degenerated afterwards, 

 and both trees having become unsightly were cut down in 

 1887. 



The average annual increase was 0"70 in each of the 

 healthier trees. 



The individual range was comparatively small in all three, 

 the highest, as might be expected, being in No. 34 — 0'60 to 

 0*30. The aggri'/jate range of the two healthiest was between 

 1-75 in 1878 and 1-05 in 1881. 



In the first depression the girth-increase of No. 34 was 

 lowered year by year, and went on decreasing to the end of 

 the period. In Nos. 35 and 4*, on the other hand, the 

 maxima actually occurred in the first year of the first depres- 

 sion, and although the increase fell off in the second and 

 third years of that depression, it was not to a serious extent, 

 and they both rallied in 1882. They also escaped the 

 depression of 1883, but No. 35 progressively declined there- 

 after. 



