PLANT SLEEP. 237 



in tlie case of the common Olovei' {Trifolium 

 repens), and in tliat of some other plants. Many 

 flowers, too, as is well known, close their petals 

 during the darkness as if for rest, and open them 

 again on the appearance of sunlight. But our 

 allusion is to the Winter sleep of plants and 

 seeds, and marvellous and interesting indeed 

 are the innumerable provisions made for pro- 

 moting, maintaining, and protecting this sleep. 

 The heralding, or rather the signalling of the 

 "Winter night-time — if the expression may be 

 used — :is the fall , of . the leaf. Then follows, in 

 deciduous trees, the falling of the sap and that 

 quiescent state which indicates <the- period of 

 rest. Roots, stem, and branches all cease their 

 active functions. Evergreens, it is true, preserve 

 their verdancy ; but there is no . upward motion 

 or progress. In their case, as in that of de- 

 ciduous plants,; the progression of vital forces is 

 arrested; but elaborate preparation; has already 

 been made for the green and floral display of the 

 succeeding seasons, and elabiDrate protection has 

 been afforded for the organs which willbe exposed 

 to the wintry cold. Summer and autumn, sun 



