6 PERIODICAL OPENING AND CLOSING OF FLOWERS. 



hour in the course of the day at which blossoms do not beg n to 

 close, yet there are a few only in which, this is the case about 

 midday, from which time the number increases, reaching its 

 maximum at six, and then again decreasing. 



The results may be arranged in a table as follows : — 



It appeal's from this table, that the hour (6 p.m.) at which the 

 greater number begin to close is twelve hours distant from that 

 (0 a.m.) at which the greater number begin to expand, and tbat 

 in general there is an opposition between the two phenomena, so 

 far as regards the fact, that at those times of the day when the 

 greater number of flowers are open, a smaller number also are 

 closed, and the contrary. 



In the table of differences in the fourth column, it is observable 

 that the difference is negative up to midnight, that is, during that 

 part of the day during which the tendency to sleep is the greatest, 

 and positive during the other twelve hours ; negative that is 

 while the sun is westward, positive while it is eastward. 



From sunrise, and so long as the height of the sun increases, 

 with few exceptions blossoms are opening ; from midday, while the 

 height is decreasing, the contrary takes place. But not only does 

 this connection between the situation of the sun and the phases 

 of the blossoms exist in the principal epocbs, but also in the 

 magnitude of the alterations in either kind of phenomenon. At 

 midnight, at the time of the inferior culmination of the sun, when 

 the expansion of the petals is at zero, we find, as also at mid-day, 

 when, as will appear afterwards, it rcacbes its maximum, there is 



