Cial of jFIototra. 295 
coloured flowers, and the Primrose leads on a long 
train of the charming children of Spring. These now 
continue to advance in increasing numbers, displaying, 
especially in May and June, their highest splendour; 
till at length the Meadow Saffron takes leave of in- 
clement Autumn, and, saturated with rain, the Mosses 
acquire fresh vigour, and open to the botanist a new 
field for investigation. 
Not less different than the period of flowering is the 
time of the opening and shutting of flowers. Some 
j)lants habitually open and close their flowers by turns : 
others are governed in these respects by the weather ; 
others again, by the length or shortness of the day: 
while some open and shut at certain hours, and thus 
iurnish materials for composing the Dial of Flowers. 
According to the observations of later botanists, the 
flowery crown of plants serves, among other things, to 
envelop the tender organs of fructification, and to pro- 
tect them from the pernicious influence of external 
agents. Those organs of fructification are the chief 
objects of the maternal care of Nature ; while shut up 
in the flower-bud, they acquire that strength and per- 
fection of parts which enable them to endure the light 
of the sun, and to perform the functions for which they 
are designed. It is not till they are capable of fulfilling 
these functions that the flower unfolds itself; but it 
again closes at such times when external influences 
might be injurious to the delicate organs of fructifica- 
tion. Many flowers can bear only the refreshing morn- 
ing air and the first rays of the sun, but remain sLu^ 
all the rest of the day. This may be particularly ob- 
served in the different species of Convolvulus, Ipomaea, 
