Nov. 1899,] BOTANICAL SOCIETY OF EDINBURGH 247 



earlier term showed also O'o per cent, decrease in July: 

 and now, in the nine-year period, show 5*5 per cent, 

 decrease in July, and O'o per cent, decrease in March. 



The Eobinia also decreases in March, and the other two 

 species have a minimum of growth ; all four species, 

 notably Robinia, improving a little in April, before their 

 May losses. The Poplars, also, recover something in June, 

 before their chief loss in July. 



The Oaks suffer a heavier loss in June than in May. 



November is the month of chief growth for Oaks, 

 Poplars, and Eobinia ; and December for Paraiso. In the 

 five-year period, Oaks and Poplars grew most in November, 

 Ilobinia in February, and Paraiso in January. 



Perhaps the chief point of contrast between the first and 

 second periods — 1885-90, and 1890-99 — is the decrease, 

 or minimum growth, in all species in March in the second 

 period, 1"9 per cent., against 23 per cent, in the first period; 

 and the very small growth in the first period, during the 

 months of June, July, and August, only S-6 per cent., 

 against 26 per cent, in these three months in the second 

 period. 



It may possibly be deduced from this that younger trees 

 have a more pronounced sleeping season than older trees, 

 and that older trees indulge in a brief preliminary siesta 

 when, in March, summer is yielding to autumn. 



If the year be divided into growing and sleeping halves — ■ 

 September to February inclusive, and March to August — 

 we find the following percentages of growth : — 



The very small growth in March — 1'9 per cent, in the 

 nine-year period, contrasted with the 23 per cent, in the 

 first period — is the reason why this table does not show any 

 very marked difference between the first and second sleeping 

 seasons, except in the case of the Robinia. 



