402 Dr Christison on the [sess. liii. 



injured, and growth retarded in at least one of them after- 

 wards. 



Depressions of 1883, 1885, 1886, and 1887. 



The rally from the first prolonged depression was neither 

 complete nor permanent. It was incomplete, because al- 

 though the amount of increase in the deciduous class in 

 1881, and in the evergTcens in 1882, was the highest ever 

 attained after that of 1878, the amounts were, nevertheless, 

 22 per cent, and 15 per cent, in these classes respectively 

 below the increase of 1878. And the rally was not per- 

 manent, as the deciduous class, after maintaining a fair 

 average of about 8-50 till 1885, fell to 7*29 in 1886, a 

 position from which but little rise took place in the two 

 following years ; while the evergreen class actually fell to 

 its absolute minimum in 1883, the very year after the rally 

 from the first depression, and although it regained a better 

 average for the next three years, it was again seriously 

 depressed in 1887. 



The most remarkable fact in regard to these depressions 

 is, that as in the prolonged depression of 1879-81, the effects 

 did not fall alike on both classes in the same years, the 

 deciduous class, as a whole, suffering in 1885, 1886, and 

 1887 ; while the evergreens, as a whole, were affected in 

 1883 and 1887. 



It would be unwanantable, however, to conclude that 

 these differences in the incidence of the depression are due 

 to class distinctions, because there are exceptions to the 

 general conduct among the species of both classes, and the 

 number of species tested is too small to establish a law of 

 general application. At the same time, the theory of class 

 distinctions is strengthened by the all but universal rallying 

 of the deciduous species in the third of the three consecu- 

 tive bad seasons, while the evergreens were almost all 

 further depi'essed in that year. 



But however it may be with the classes, the differences in 

 the incidence upon the species are indubitable, and deserve a 

 detailed investigation. 



1883. — As we have just .seen, the evergreen species rallied 

 from the severe depressions of 1879-80-81 from 6"16 in 

 1881 to 7*05 in 1882; but tliey had no sooner done so than 



