02 PERIODIC PHENOMENA OF VEGETABLE LIFE. 



In order to compare these phenomena on as large a number of 

 stations as possible, I have endeavoured to procure mean terms, 

 for the commencement of the most important periods of vegetation, 

 by an attentive study of data furnished by the country people, and 

 of notes consigned in old almanacs bj r attentive cultivators, often 

 extending over periods of from six to sixteen years, and by my 

 own observations in the different places where I have resided in 

 different years. I have only admitted with great caution infor- 

 mation communicated verbally : I have generally addressed the 

 same questions to different persons, and I have thus been able the 

 better to test the veracity of verbal communications, which, how- 

 ever, have generally agreed tolerably well with each other. This 

 was a natural consequence of the attention bestowed on the 

 observation of these phenomena. 



My own observations comprise only some portions of the year ; 

 for great altitudes, where vegetation only commences in June or 

 July, the memoranda taken in summer and autumn are sufficient, 

 and when at other times I was in inhabited valleys, they served me 

 as a check upon the memoranda I had collected. But the number 

 of plants I could admit in my tables was necessarily very limited. 

 In many places, among large leaf-bearing trees, there were only 

 Cherries and Ashes. The species of small plants vary so much with 

 the altitudes, that often the whole of those employed for this purpose 

 and enumerated in the copious catalogues of Quetelet were wanting. 

 I could, however, follow the Beech, the Strawberry, the Walnut, 

 the Cherry, the Elder, the Lilac, the Violet, and some others 

 to great altitudes towards the extreme limits of their circumscrip- 

 tion. The Cerealia interested me more especially, as with them 

 it was easy to record the periods of sowing, of flowering, and of 

 maturity, in different places, from a great number of observations. 



We should not, however, neglect perennial herbaceous plants, 

 which, not being subject to the chances of cultivation, can obey 

 more freely the direct influence of spring, and are better suited to 

 the observation of the early development of vegetable life. In 

 Cereals, on the contrary, although the commencement of vegetation 

 is, even with them, comprised within fixed limits, yet it is not 

 wholly independent of arbitrary circumstances, and all its periods 

 may be changed if the time of sowing be delayed. 



Winter Cereals are, however, much freer from this defect, for 

 differences of a week or a fortnight in the time of sowing are 

 compensated during the long continuance of the winter months 



Summer Cereals appear to be much more influenced by these 



