BECOBDS Off THE tiSASONS AND TEE YEARS 415 



leafing, and falling of the leaves of certain plants 

 is, therefore, of interest, not only from the side of 

 plant -study, but from the side of climate- study. 

 Plants record all the features of the passing cli- 

 mate, as warmth, moisture, sunshine, and the vari- 

 ous inter-relations of them. The science or study 

 which considers the relationship of local climate 

 to the periodical phenomena of animals and plants 

 is phenology. 



526a. Phenology is a eontraetion of phenomenology. It is to be 

 noted that its proper subject is climate, as expressed in terms of 

 plant and animal periodicities, not plants and animals as influenced 

 by climate. 



527. If data are to have any value in recording 

 the changes of the seasons, and the climates of the 

 years, they must be made with a definite purpose, 

 and be continued for a series of years ; and, so 

 far as possible, records should be taken from the 

 same plants year by year, if these plants represent 

 average conditions. 



528. The subjects of phenological inquiry may be 

 classified as follows : to determine the general oncom- 

 ing of spring ; to determine the fitful or variable fea- 

 tures of spring ; to determine the epoch of the full 

 activity of the advancing season ; to determine the 

 active physiological epoch of the year ; to deter- 

 mine the maturation of the season ; to determine the 

 oncoming of the decline of fall ; to determine the 



